diff options
Diffstat (limited to 'zdump.8.txt')
| -rw-r--r-- | zdump.8.txt | 116 |
1 files changed, 58 insertions, 58 deletions
diff --git a/zdump.8.txt b/zdump.8.txt index bcdd99b03c9e..35a341009c0a 100644 --- a/zdump.8.txt +++ b/zdump.8.txt @@ -16,77 +16,77 @@ OPTIONS --help Output short usage message and exit. - -i Output a description of time intervals. For each timezone on - the command line, output an interval-format description of the + -i Output a description of time intervals. For each timezone on + the command line, output an interval-format description of the timezone. See "INTERVAL FORMAT" below. - -v Output a verbose description of time intervals. For each + -v Output a verbose description of time intervals. For each timezone on the command line, print the times at the two extreme - time values, the times (if present) at and just beyond the - boundaries of years that localtime(3) and gmtime(3) can - represent, and the times both one second before and exactly at - each detected time discontinuity. Each line is followed by - isdst=D where D is positive, zero, or negative depending on - whether the given time is daylight saving time, standard time, - or an unknown time type, respectively. Each line is also - followed by gmtoff=N if the given local time is known to be N + time values, the times (if present) at and just beyond the + boundaries of years that localtime(3) and gmtime(3) can + represent, and the times both one second before and exactly at + each detected time discontinuity. Each line is followed by + isdst=D where D is positive, zero, or negative depending on + whether the given time is daylight saving time, standard time, + or an unknown time type, respectively. Each line is also + followed by gmtoff=N if the given local time is known to be N seconds east of Greenwich. - -V Like -v, except omit output concerning extreme time and year + -V Like -v, except omit output concerning extreme time and year values. This generates output that is easier to compare to that of implementations with different time representations. -c [loyear,]hiyear - Cut off interval output at the given year(s). Cutoff times are - computed using the proleptic Gregorian calendar with year 0 and - with Universal Time (UT) ignoring leap seconds. Cutoffs are at - the start of each year, where the lower-bound timestamp is - inclusive and the upper is exclusive; for example, -c 1970,2070 - selects transitions on or after 1970-01-01 00:00:00 UTC and - before 2070-01-01 00:00:00 UTC. The default cutoff is + Cut off interval output at the given year(s). Cutoff times are + computed using the proleptic Gregorian calendar with year 0 and + with Universal Time (UT) ignoring leap seconds. Cutoffs are at + the start of each year, where the lower-bound timestamp is + inclusive and the upper is exclusive; for example, -c 1970,2070 + selects transitions on or after 1970-01-01 00:00:00 UTC and + before 2070-01-01 00:00:00 UTC. The default cutoff is -500,2500. -t [lotime,]hitime - Cut off interval output at the given time(s), given in decimal - seconds since 1970-01-01 00:00:00 Coordinated Universal Time - (UTC). The timezone determines whether the count includes leap - seconds. As with -c, the cutoff's lower bound is inclusive and + Cut off interval output at the given time(s), given in decimal + seconds since 1970-01-01 00:00:00 Coordinated Universal Time + (UTC). The timezone determines whether the count includes leap + seconds. As with -c, the cutoff's lower bound is inclusive and its upper bound is exclusive. INTERVAL FORMAT - The interval format is a compact text representation that is intended - to be both human- and machine-readable. It consists of an empty line, - then a line "TZ=string" where string is a double-quoted string giving + The interval format is a compact text representation that is intended + to be both human- and machine-readable. It consists of an empty line, + then a line "TZ=string" where string is a double-quoted string giving the timezone, a second line "- - interval" describing the time interval - before the first transition if any, and zero or more following lines - "date time interval", one line for each transition time and following + before the first transition if any, and zero or more following lines + "date time interval", one line for each transition time and following interval. Fields are separated by single tabs. Dates are in yyyy-mm-dd format and times are in 24-hour hh:mm:ss format where hh<24. Times are in local time immediately after the transition. - A time interval description consists of a UT offset in signed +-hhmmss - format, a time zone abbreviation, and an isdst flag. An abbreviation - that equals the UT offset is omitted; other abbreviations are double- - quoted strings unless they consist of one or more alphabetic - characters. An isdst flag is omitted for standard time, and otherwise - is a decimal integer that is unsigned and positive (typically 1) for + A time interval description consists of a UT offset in signed +-hhmmss + format, a time zone abbreviation, and an isdst flag. An abbreviation + that equals the UT offset is omitted; other abbreviations are double- + quoted strings unless they consist of one or more alphabetic + characters. An isdst flag is omitted for standard time, and otherwise + is a decimal integer that is unsigned and positive (typically 1) for daylight saving time and negative for unknown. In times and in UT offsets with absolute value less than 100 hours, the - seconds are omitted if they are zero, and the minutes are also omitted + seconds are omitted if they are zero, and the minutes are also omitted if they are also zero. Positive UT offsets are east of Greenwich. The UT offset -00 denotes a UT placeholder in areas where the actual offset - is unspecified; by convention, this occurs when the UT offset is zero + is unspecified; by convention, this occurs when the UT offset is zero and the time zone abbreviation begins with "-" or is "zzz". - In double-quoted strings, escape sequences represent unusual + In double-quoted strings, escape sequences represent unusual characters. The escape sequences are \s for space, and \", \\, \f, \n, - \r, \t, and \v with their usual meaning in the C programming language. - E.g., the double-quoted string ""CET\s\"\\"" represents the character + \r, \t, and \v with their usual meaning in the C programming language. + E.g., the double-quoted string ""CET\s\"\\"" represents the character sequence "CET "\". - Here is an example of the output, with the leading empty line omitted. - (This example is shown with tab stops set far enough apart so that the + Here is an example of the output, with the leading empty line omitted. + (This example is shown with tab stops set far enough apart so that the tabbed columns line up.) TZ="Pacific/Honolulu" @@ -100,14 +100,14 @@ INTERVAL FORMAT 1947-06-08 02:30 -10 HST Here, local time begins 10 hours, 31 minutes and 26 seconds west of UT, - and is a standard time abbreviated LMT. Immediately after the first - transition, the date is 1896-01-13 and the time is 12:01:26, and the - following time interval is 10.5 hours west of UT, a standard time - abbreviated HST. Immediately after the second transition, the date is - 1933-04-30 and the time is 03:00:00 and the following time interval is - 9.5 hours west of UT, is abbreviated HDT, and is daylight saving time. - Immediately after the last transition the date is 1947-06-08 and the - time is 02:30:00, and the following time interval is 10 hours west of + and is a standard time abbreviated LMT. Immediately after the first + transition, the date is 1896-01-13 and the time is 12:01:26, and the + following time interval is 10.5 hours west of UT, a standard time + abbreviated HST. Immediately after the second transition, the date is + 1933-04-30 and the time is 03:00:00 and the following time interval is + 9.5 hours west of UT, is abbreviated HDT, and is daylight saving time. + Immediately after the last transition the date is 1947-06-08 and the + time is 02:30:00, and the following time interval is 10 hours west of UT, a standard time abbreviated HST. Here are excerpts from another example: @@ -122,20 +122,20 @@ INTERVAL FORMAT 2014-10-26 01 +03 2016-03-27 03 +04 - This time zone is east of UT, so its UT offsets are positive. Also, - many of its time zone abbreviations are omitted since they duplicate + This time zone is east of UT, so its UT offsets are positive. Also, + many of its time zone abbreviations are omitted since they duplicate the text of the UT offset. LIMITATIONS - Time discontinuities are found by sampling the results returned by - localtime(3) at twelve-hour intervals. This works in all real-world + Time discontinuities are found by sampling the results returned by + localtime(3) at twelve-hour intervals. This works in all real-world cases; one can construct artificial time zones for which this fails. - In the -v and -V output, "UT" denotes the value returned by gmtime(3), - which uses UTC for modern timestamps and some other UT flavor for - timestamps that predate the introduction of UTC. No attempt is - currently made to have the output use "UTC" for newer and "UT" for - older timestamps, partly because the exact date of the introduction of + In the -v and -V output, "UT" denotes the value returned by gmtime(3), + which uses UTC for modern timestamps and some other UT flavor for + timestamps that predate the introduction of UTC. No attempt is + currently made to have the output use "UTC" for newer and "UT" for + older timestamps, partly because the exact date of the introduction of UTC is problematic. SEE ALSO |