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diff --git a/man8/zic.8 b/man8/zic.8 deleted file mode 100644 index c467efefe..000000000 --- a/man8/zic.8 +++ /dev/null @@ -1,903 +0,0 @@ -.\" This file is in the public domain, so clarified as of -.\" 2009-05-17 by Arthur David Olson. -.TH zic 8 "" "Time Zone Database" -.SH NAME -zic \- timezone compiler -.SH SYNOPSIS -.B zic -[ -.I option -\&... ] [ -.I filename -\&... ] -.SH DESCRIPTION -.ie '\(lq'' .ds lq \&"\" -.el .ds lq \(lq\" -.ie '\(rq'' .ds rq \&"\" -.el .ds rq \(rq\" -.de q -\\$3\*(lq\\$1\*(rq\\$2 -.. -.ie '\(la'' .ds < < -.el .ds < \(la -.ie '\(ra'' .ds > > -.el .ds > \(ra -.ie \n(.g \{\ -. ds : \: -. ds - \f(CR-\fP -.\} -.el \{\ -. ds : -. ds - \- -.\} -.ds d " degrees -.ds m " minutes -.ds s " seconds -.ds _ " \& -.if t \{\ -. if \n(.g .if c \(de .if c \(fm .if c \(sd \{\ -. ds d \(de -. ds m \(fm -. ds s \(sd -. ds _ \| -. \} -.\} -The -.B zic -program reads text from the file(s) named on the command line -and creates the timezone information format (TZif) files -specified in this input. -If a -.I filename -is -.q "\*-" , -standard input is read. -.SH OPTIONS -.TP -.B "\*-\*-version" -Output version information and exit. -.TP -.B \*-\*-help -Output short usage message and exit. -.TP -.BI "\*-b " bloat -Output backward-compatibility data as specified by -.IR bloat . -If -.I bloat -is -.BR fat , -generate additional data entries that work around potential bugs or -incompatibilities in older software, such as software that mishandles -the 64-bit generated data. -If -.I bloat -is -.BR slim , -keep the output files small; this can help check for the bugs -and incompatibilities. -The default is -.BR slim , -as software that mishandles 64-bit data typically -mishandles timestamps after the year 2038 anyway. -Also see the -.B \*-r -option for another way to alter output size. -.TP -.BI "\*-d " directory -Create time conversion information files in the named directory rather than -in the standard directory named below. -.TP -.BI "\*-l " timezone -Use -.I timezone -as local time. -.B zic -will act as if the input contained a link line of the form -.sp -.ti +.5i -.ta \w'Link\0\0'u +\w'\fItimezone\fP\0\0'u -Link \fItimezone\fP localtime -.sp -If -.I timezone -is -.BR \*- , -any already-existing link is removed. -.TP -.BI "\*-L " leapsecondfilename -Read leap second information from the file with the given name. -If this option is not used, -no leap second information appears in output files. -.TP -.BI "\*-p " timezone -Use -.IR timezone 's -rules when handling nonstandard -TZ strings like "EET\*-2EEST" that lack transition rules. -.B zic -will act as if the input contained a link line of the form -.sp -.ti +.5i -Link \fItimezone\fP posixrules -.sp -Unless -.I timezone is -.q "\*-" , -this option is obsolete and poorly supported. -Among other things it should not be used for timestamps after the year 2037, -and it should not be combined with -.B "\*-b slim" -if -.IR timezone 's -transitions are at standard time or Universal Time (UT) instead of local time. -.sp -If -.I timezone -is -.BR \*- , -any already-existing link is removed. -.TP -.BR "\*-r " "[\fB@\fP\fIlo\fP][\fB/@\fP\fIhi\fP]" -Limit the applicability of output files -to timestamps in the range from -.I lo -(inclusive) to -.I hi -(exclusive), where -.I lo -and -.I hi -are possibly signed decimal counts of seconds since the Epoch -(1970-01-01 00:00:00 UTC). -Omitted counts default to extreme values. -The output files use UT offset 0 and abbreviation -.q "\*-00" -in place of the omitted timestamp data. -For example, -.q "zic \*-r @0" -omits data intended for negative timestamps (i.e., before the Epoch), and -.q "zic \*-r @0/@2147483648" -outputs data intended only for nonnegative timestamps that fit into -31-bit signed integers. -On platforms with GNU -.BR date , -.q "zic \*-r @$(date +%s)" -omits data intended for past timestamps. -Although this option typically reduces the output file's size, -the size can increase due to the need to represent the timestamp range -boundaries, particularly if -.I hi -causes a TZif file to contain explicit entries for -.RI pre- hi -transitions rather than concisely representing them -with an extended POSIX TZ string. -Also see the -.B "\*-b slim" -option for another way to shrink output size. -.TP -.BI "\*-R @" hi -Generate redundant trailing explicit transitions for timestamps -that occur less than -.I hi -seconds since the Epoch, even though the transitions could be -more concisely represented via the extended POSIX TZ string. -This option does not affect the represented timestamps. -Although it accommodates nonstandard TZif readers -that ignore the extended POSIX TZ string, -it increases the size of the altered output files. -.TP -.BI "\*-t " file -When creating local time information, put the configuration link in -the named file rather than in the standard location. -.TP -.B \*-v -Be more verbose, and complain about the following situations: -.RS -.PP -The input specifies a link to a link, -something not supported by some older parsers, including -.B zic -itself through release 2022e. -.PP -A year that appears in a data file is outside the range -of representable years. -.PP -A time of 24:00 or more appears in the input. -Pre-1998 versions of -.B zic -prohibit 24:00, and pre-2007 versions prohibit times greater than 24:00. -.PP -A rule goes past the start or end of the month. -Pre-2004 versions of -.B zic -prohibit this. -.PP -A time zone abbreviation uses a -.B %z -format. -Pre-2015 versions of -.B zic -do not support this. -.PP -A timestamp contains fractional seconds. -Pre-2018 versions of -.B zic -do not support this. -.PP -The input contains abbreviations that are mishandled by pre-2018 versions of -.B zic -due to a longstanding coding bug. -These abbreviations include -.q L -for -.q Link , -.q mi -for -.q min , -.q Sa -for -.q Sat , -and -.q Su -for -.q Sun . -.PP -The output file does not contain all the information about the -long-term future of a timezone, because the future cannot be summarized as -an extended POSIX TZ string. For example, as of 2023 this problem -occurs for Morocco's daylight-saving rules, as these rules are based -on predictions for when Ramadan will be observed, something that -an extended POSIX TZ string cannot represent. -.PP -The output contains data that may not be handled properly by client -code designed for older -.B zic -output formats. These compatibility issues affect only timestamps -before 1970 or after the start of 2038. -.PP -The output contains a truncated leap second table, -which can cause some older TZif readers to misbehave. -This can occur if the -.B "\*-L" -option is used, and either an Expires line is present or -the -.B "\*-r" -option is also used. -.PP -The output file contains more than 1200 transitions, -which may be mishandled by some clients. -The current reference client supports at most 2000 transitions; -pre-2014 versions of the reference client support at most 1200 -transitions. -.PP -A time zone abbreviation has fewer than 3 or more than 6 characters. -POSIX requires at least 3, and requires implementations to support -at least 6. -.PP -An output file name contains a byte that is not an ASCII letter, -.q "\*-" , -.q "/" , -or -.q "_" ; -or it contains a file name component that contains more than 14 bytes -or that starts with -.q "\*-" . -.RE -.SH FILES -Input files use the format described in this section; output files use -.BR tzfile (5) -format. -.PP -Input files should be text files, that is, they should be a series of -zero or more lines, each ending in a newline byte and containing at -most 2048 bytes counting the newline, and without any NUL bytes. -The input text's encoding -is typically UTF-8 or ASCII; it should have a unibyte representation -for the POSIX Portable Character Set (PPCS) -\*<https://pubs\*:.opengroup\*:.org/\*:onlinepubs/\*:9699919799/\*:basedefs/\*:V1_chap06\*:.html\*> -and the encoding's non-unibyte characters should consist entirely of -non-PPCS bytes. Non-PPCS characters typically occur only in comments: -although output file names and time zone abbreviations can contain -nearly any character, other software will work better if these are -limited to the restricted syntax described under the -.B \*-v -option. -.PP -Input lines are made up of fields. -Fields are separated from one another by one or more white space characters. -The white space characters are space, form feed, carriage return, newline, -tab, and vertical tab. -Leading and trailing white space on input lines is ignored. -An unquoted sharp character (#) in the input introduces a comment which extends -to the end of the line the sharp character appears on. -White space characters and sharp characters may be enclosed in double quotes -(") if they're to be used as part of a field. -Any line that is blank (after comment stripping) is ignored. -Nonblank lines are expected to be of one of three types: -rule lines, zone lines, and link lines. -.PP -Names must be in English and are case insensitive. -They appear in several contexts, and include month and weekday names -and keywords such as -.BR "maximum" , -.BR "only" , -.BR "Rolling" , -and -.BR "Zone" . -A name can be abbreviated by omitting all but an initial prefix; any -abbreviation must be unambiguous in context. -.PP -A rule line has the form -.nf -.ti +.5i -.ta \w'Rule\0\0'u +\w'NAME\0\0'u +\w'FROM\0\0'u +\w'1973\0\0'u +\w'\*-\0\0'u +\w'Apr\0\0'u +\w'lastSun\0\0'u +\w'2:00w\0\0'u +\w'1:00d\0\0'u -.sp -Rule NAME FROM TO \*- IN ON AT SAVE LETTER/S -.sp -For example: -.ti +.5i -.sp -Rule US 1967 1973 \*- Apr lastSun 2:00w 1:00d D -.sp -.fi -The fields that make up a rule line are: -.TP "\w'LETTER/S'u" -.B NAME -Gives the name of the rule set that contains this line. -The name must start with a character that is neither -an ASCII digit nor -.q \*- -nor -.q + . -To allow for future extensions, -an unquoted name should not contain characters from the set -.ie \n(.g .q \f(CR!$%&\(aq()*,/:;<=>?@[\e]\(ha\(ga{|}\(ti\fP . -.el .ie t .q \f(CW!$%&'()*,/:;<=>?@[\e]^\(ga{|}~\fP . -.el .q !$%&'()*,/:;<=>?@[\e]^`{|}~ . -.TP -.B FROM -Gives the first year in which the rule applies. -Any signed integer year can be supplied; the proleptic Gregorian calendar -is assumed, with year 0 preceding year 1. -The word -.B minimum -(or an abbreviation) means the indefinite past. -The word -.B maximum -(or an abbreviation) means the indefinite future. -Rules can describe times that are not representable as time values, -with the unrepresentable times ignored; this allows rules to be portable -among hosts with differing time value types. -.TP -.B TO -Gives the final year in which the rule applies. -In addition to -.B minimum -and -.B maximum -(as above), -the word -.B only -(or an abbreviation) -may be used to repeat the value of the -.B FROM -field. -.TP -.B \*- -Is a reserved field and should always contain -.q \*- -for compatibility with older versions of -.BR zic . -It was previously known as the -.B TYPE -field, which could contain values to allow a -separate script to further restrict in which -.q types -of years the rule would apply. -.TP -.B IN -Names the month in which the rule takes effect. -Month names may be abbreviated. -.TP -.B ON -Gives the day on which the rule takes effect. -Recognized forms include: -.nf -.in +.5i -.sp -.ta \w'Sun<=25\0\0'u -5 the fifth of the month -lastSun the last Sunday in the month -lastMon the last Monday in the month -Sun>=8 first Sunday on or after the eighth -Sun<=25 last Sunday on or before the 25th -.fi -.in -.5i -.sp -A weekday name (e.g., -.BR "Sunday" ) -or a weekday name preceded by -.q "last" -(e.g., -.BR "lastSunday" ) -may be abbreviated or spelled out in full. -There must be no white space characters within the -.B ON -field. -The -.q <= -and -.q >= -constructs can result in a day in the neighboring month; -for example, the IN-ON combination -.q "Oct Sun>=31" -stands for the first Sunday on or after October 31, -even if that Sunday occurs in November. -.TP -.B AT -Gives the time of day at which the rule takes effect, -relative to 00:00, the start of a calendar day. -Recognized forms include: -.nf -.in +.5i -.sp -.ta \w'00:19:32.13\0\0'u -2 time in hours -2:00 time in hours and minutes -01:28:14 time in hours, minutes, and seconds -00:19:32.13 time with fractional seconds -12:00 midday, 12 hours after 00:00 -15:00 3 PM, 15 hours after 00:00 -24:00 end of day, 24 hours after 00:00 -260:00 260 hours after 00:00 -\*-2:30 2.5 hours before 00:00 -\*- equivalent to 0 -.fi -.in -.5i -.sp -Although -.B zic -rounds times to the nearest integer second -(breaking ties to the even integer), the fractions may be useful -to other applications requiring greater precision. -The source format does not specify any maximum precision. -Any of these forms may be followed by the letter -.B w -if the given time is local or -.q "wall clock" -time, -.B s -if the given time is standard time without any adjustment for daylight saving, -or -.B u -(or -.B g -or -.BR z ) -if the given time is universal time; -in the absence of an indicator, -local (wall clock) time is assumed. -These forms ignore leap seconds; for example, -if a leap second occurs at 00:59:60 local time, -.q "1:00" -stands for 3601 seconds after local midnight instead of the usual 3600 seconds. -The intent is that a rule line describes the instants when a -clock/calendar set to the type of time specified in the -.B AT -field would show the specified date and time of day. -.TP -.B SAVE -Gives the amount of time to be added to local standard time when the rule is in -effect, and whether the resulting time is standard or daylight saving. -This field has the same format as the -.B AT -field -except with a different set of suffix letters: -.B s -for standard time and -.B d -for daylight saving time. -The suffix letter is typically omitted, and defaults to -.B s -if the offset is zero and to -.B d -otherwise. -Negative offsets are allowed; in Ireland, for example, daylight saving -time is observed in winter and has a negative offset relative to -Irish Standard Time. -The offset is merely added to standard time; for example, -.B zic -does not distinguish a 10:30 standard time plus an 0:30 -.B SAVE -from a 10:00 standard time plus a 1:00 -.BR SAVE . -.TP -.B LETTER/S -Gives the -.q "variable part" -(for example, the -.q "S" -or -.q "D" -in -.q "EST" -or -.q "EDT" ) -of time zone abbreviations to be used when this rule is in effect. -If this field is -.q \*- , -the variable part is null. -.PP -A zone line has the form -.sp -.nf -.ti +.5i -.ta \w'Zone\0\0'u +\w'Asia/Amman\0\0'u +\w'STDOFF\0\0'u +\w'Jordan\0\0'u +\w'FORMAT\0\0'u -Zone NAME STDOFF RULES FORMAT [UNTIL] -.sp -For example: -.sp -.ti +.5i -Zone Asia/Amman 2:00 Jordan EE%sT 2017 Oct 27 01:00 -.sp -.fi -The fields that make up a zone line are: -.TP "\w'STDOFF'u" -.B NAME -The name of the timezone. -This is the name used in creating the time conversion information file for the -timezone. -It should not contain a file name component -.q ".\&" -or -.q ".." ; -a file name component is a maximal substring that does not contain -.q "/" . -.TP -.B STDOFF -The amount of time to add to UT to get standard time, -without any adjustment for daylight saving. -This field has the same format as the -.B AT -and -.B SAVE -fields of rule lines, except without suffix letters; -begin the field with a minus sign if time must be subtracted from UT. -.TP -.B RULES -The name of the rules that apply in the timezone or, -alternatively, a field in the same format as a rule-line SAVE column, -giving the amount of time to be added to local standard time -and whether the resulting time is standard or daylight saving. -If this field is -.B \*- -then standard time always applies. -When an amount of time is given, only the sum of standard time and -this amount matters. -.TP -.B FORMAT -The format for time zone abbreviations. -The pair of characters -.B %s -is used to show where the -.q "variable part" -of the time zone abbreviation goes. -Alternatively, a format can use the pair of characters -.B %z -to stand for the UT offset in the form -.RI \(+- hh , -.RI \(+- hhmm , -or -.RI \(+- hhmmss , -using the shortest form that does not lose information, where -.IR hh , -.IR mm , -and -.I ss -are the hours, minutes, and seconds east (+) or west (\-) of UT. -Alternatively, -a slash (/) -separates standard and daylight abbreviations. -To conform to POSIX, a time zone abbreviation should contain only -alphanumeric ASCII characters, -.q "+" -and -.q "\*-". -By convention, the time zone abbreviation -.q "\*-00" -is a placeholder that means local time is unspecified. -.TP -.B UNTIL -The time at which the UT offset or the rule(s) change for a location. -It takes the form of one to four fields YEAR [MONTH [DAY [TIME]]]. -If this is specified, -the time zone information is generated from the given UT offset -and rule change until the time specified, which is interpreted using -the rules in effect just before the transition. -The month, day, and time of day have the same format as the IN, ON, and AT -fields of a rule; trailing fields can be omitted, and default to the -earliest possible value for the missing fields. -.IP -The next line must be a -.q "continuation" -line; this has the same form as a zone line except that the -string -.q "Zone" -and the name are omitted, as the continuation line will -place information starting at the time specified as the -.q "until" -information in the previous line in the file used by the previous line. -Continuation lines may contain -.q "until" -information, just as zone lines do, indicating that the next line is a further -continuation. -.PP -If a zone changes at the same instant that a rule would otherwise take -effect in the earlier zone or continuation line, the rule is ignored. -A zone or continuation line -.I L -with a named rule set starts with standard time by default: -that is, any of -.IR L 's -timestamps preceding -.IR L 's -earliest rule use the rule in effect after -.IR L 's -first transition into standard time. -In a single zone it is an error if two rules take effect at the same -instant, or if two zone changes take effect at the same instant. -.PP -If a continuation line subtracts -.I N -seconds from the UT offset after a transition that would be -interpreted to be later if using the continuation line's UT offset and -rules, the -.q "until" -time of the previous zone or continuation line is interpreted -according to the continuation line's UT offset and rules, and any rule -that would otherwise take effect in the next -.I N -seconds is instead assumed to take effect simultaneously. -For example: -.br -.ne 7 -.nf -.in +2m -.ta \w'# Rule\0\0'u +\w'NAME\0\0'u +\w'FROM\0\0'u +\w'2006\0\0'u +\w'\*-\0\0'u +\w'Oct\0\0'u +\w'lastSun\0\0'u +\w'2:00\0\0'u +\w'SAVE\0\0'u -.sp -# Rule NAME FROM TO \*- IN ON AT SAVE LETTER/S -Rule US 1967 2006 - Oct lastSun 2:00 0 S -Rule US 1967 1973 - Apr lastSun 2:00 1:00 D -.ta \w'Zone\0\0America/Menominee\0\0'u +\w'STDOFF\0\0'u +\w'RULES\0\0'u +\w'FORMAT\0\0'u -# Zone\0\0NAME STDOFF RULES FORMAT [UNTIL] -Zone\0\0America/Menominee \*-5:00 \*- EST 1973 Apr 29 2:00 - \*-6:00 US C%sT -.sp -.in -.fi -Here, an incorrect reading would be there were two clock changes on 1973-04-29, -the first from 02:00 EST (\*-05) to 01:00 CST (\*-06), -and the second an hour later from 02:00 CST (\*-06) to 03:00 CDT (\*-05). -However, -.B zic -interprets this more sensibly as a single transition from 02:00 CST (\*-05) to -02:00 CDT (\*-05). -.PP -A link line has the form -.sp -.nf -.ti +.5i -.ta \w'Link\0\0'u +\w'Europe/Istanbul\0\0'u -Link TARGET LINK-NAME -.sp -For example: -.sp -.ti +.5i -Link Europe/Istanbul Asia/Istanbul -.sp -.fi -The -.B TARGET -field should appear as the -.B NAME -field in some zone line or as the -.B LINK-NAME -field in some link line. -The -.B LINK-NAME -field is used as an alternative name for that zone; -it has the same syntax as a zone line's -.B NAME -field. -Links can chain together, although the behavior is unspecified if a -chain of one or more links does not terminate in a Zone name. -A link line can appear before the line that defines the link target. -For example: -.sp -.ne 3 -.nf -.in +2m -.ta \w'Zone\0\0'u +\w'Greenwich\0\0'u -Link Greenwich G_M_T -Link Etc/GMT Greenwich -Zone Etc/GMT\0\00\0\0\*-\0\0GMT -.sp -.in -.fi -The two links are chained together, and G_M_T, Greenwich, and Etc/GMT -all name the same zone. -.PP -Except for continuation lines, -lines may appear in any order in the input. -However, the behavior is unspecified if multiple zone or link lines -define the same name. -.PP -The file that describes leap seconds can have leap lines and an -expiration line. -Leap lines have the following form: -.nf -.ti +.5i -.ta \w'Leap\0\0'u +\w'YEAR\0\0'u +\w'MONTH\0\0'u +\w'DAY\0\0'u +\w'HH:MM:SS\0\0'u +\w'CORR\0\0'u -.sp -Leap YEAR MONTH DAY HH:MM:SS CORR R/S -.sp -For example: -.ti +.5i -.sp -Leap 2016 Dec 31 23:59:60 + S -.sp -.fi -The -.BR YEAR , -.BR MONTH , -.BR DAY , -and -.B HH:MM:SS -fields tell when the leap second happened. -The -.B CORR -field -should be -.q "+" -if a second was added -or -.q "\*-" -if a second was skipped. -The -.B R/S -field -should be (an abbreviation of) -.q "Stationary" -if the leap second time given by the other fields should be interpreted as UTC -or -(an abbreviation of) -.q "Rolling" -if the leap second time given by the other fields should be interpreted as -local (wall clock) time. -.PP -Rolling leap seconds were implemented back when it was not -clear whether common practice was rolling or stationary, -with concerns that one would see -Times Square ball drops where there'd be a -.q "3... 2... 1... leap... Happy New Year" -countdown, placing the leap second at -midnight New York time rather than midnight UTC. -However, this countdown style does not seem to have caught on, -which means rolling leap seconds are not used in practice; -also, they are not supported if the -.B \*-r -option is used. -.PP -The expiration line, if present, has the form: -.nf -.ti +.5i -.ta \w'Expires\0\0'u +\w'YEAR\0\0'u +\w'MONTH\0\0'u +\w'DAY\0\0'u -.sp -Expires YEAR MONTH DAY HH:MM:SS -.sp -For example: -.ti +.5i -.sp -Expires 2020 Dec 28 00:00:00 -.sp -.fi -The -.BR YEAR , -.BR MONTH , -.BR DAY , -and -.B HH:MM:SS -fields give the expiration timestamp in UTC for the leap second table. -.br -.ne 22 -.SH "EXTENDED EXAMPLE" -Here is an extended example of -.B zic -input, intended to illustrate many of its features. -.nf -.in +2m -.ta \w'# Rule\0\0'u +\w'NAME\0\0'u +\w'FROM\0\0'u +\w'1973\0\0'u +\w'\*-\0\0'u +\w'Apr\0\0'u +\w'lastSun\0\0'u +\w'2:00\0\0'u +\w'SAVE\0\0'u -.sp -# Rule NAME FROM TO \*- IN ON AT SAVE LETTER/S -Rule Swiss 1941 1942 \*- May Mon>=1 1:00 1:00 S -Rule Swiss 1941 1942 \*- Oct Mon>=1 2:00 0 \*- -.sp .5 -Rule EU 1977 1980 \*- Apr Sun>=1 1:00u 1:00 S -Rule EU 1977 only \*- Sep lastSun 1:00u 0 \*- -Rule EU 1978 only \*- Oct 1 1:00u 0 \*- -Rule EU 1979 1995 \*- Sep lastSun 1:00u 0 \*- -Rule EU 1981 max \*- Mar lastSun 1:00u 1:00 S -Rule EU 1996 max \*- Oct lastSun 1:00u 0 \*- -.sp -.ta \w'# Zone\0\0'u +\w'Europe/Zurich\0\0'u +\w'0:29:45.50\0\0'u +\w'RULES\0\0'u +\w'FORMAT\0\0'u -# Zone NAME STDOFF RULES FORMAT [UNTIL] -Zone Europe/Zurich 0:34:08 \*- LMT 1853 Jul 16 - 0:29:45.50 \*- BMT 1894 Jun - 1:00 Swiss CE%sT 1981 - 1:00 EU CE%sT -.sp -Link Europe/Zurich Europe/Vaduz -.sp -.in -.fi -In this example, the EU rules are for the European Union -and for its predecessor organization, the European Communities. -The timezone is named Europe/Zurich and it has the alias Europe/Vaduz. -This example says that Zurich was 34 minutes and 8 -seconds east of UT until 1853-07-16 at 00:00, when the legal offset -was changed to -7\*d\*_26\*m\*_22.50\*s, -which works out to 0:29:45.50; -.B zic -treats this by rounding it to 0:29:46. -After 1894-06-01 at 00:00 the UT offset became one hour -and Swiss daylight saving rules (defined with lines beginning with -.q "Rule Swiss") -apply. From 1981 to the present, EU daylight saving rules have -applied, and the UTC offset has remained at one hour. -.PP -In 1941 and 1942, daylight saving time applied from the first Monday -in May at 01:00 to the first Monday in October at 02:00. -The pre-1981 EU daylight-saving rules have no effect -here, but are included for completeness. Since 1981, daylight -saving has begun on the last Sunday in March at 01:00 UTC. -Until 1995 it ended the last Sunday in September at 01:00 UTC, -but this changed to the last Sunday in October starting in 1996. -.PP -For purposes of display, -.q "LMT" -and -.q "BMT" -were initially used, respectively. Since -Swiss rules and later EU rules were applied, the time zone abbreviation -has been CET for standard time and CEST for daylight saving -time. -.SH FILES -.TP -.I /etc/localtime -Default local timezone file. -.TP -.I /usr/share/zoneinfo -Default timezone information directory. -.SH NOTES -For areas with more than two types of local time, -you may need to use local standard time in the -.B AT -field of the earliest transition time's rule to ensure that -the earliest transition time recorded in the compiled file is correct. -.PP -If, -for a particular timezone, -a clock advance caused by the start of daylight saving -coincides with and is equal to -a clock retreat caused by a change in UT offset, -.B zic -produces a single transition to daylight saving at the new UT offset -without any change in local (wall clock) time. -To get separate transitions -use multiple zone continuation lines -specifying transition instants using universal time. -.SH SEE ALSO -.BR tzfile (5), -.BR zdump (8) |