119 lines
3.7 KiB
Groff
119 lines
3.7 KiB
Groff
|
||
|
||
TZ(5) Minix Programmer's Manual TZ(5)
|
||
|
||
|
||
NAME
|
||
TZ - Time zone environment variable
|
||
|
||
SYNOPSIS
|
||
TZ=zone[-]offset[dst[offset][,start[/time],end[/time]]]
|
||
|
||
DESCRIPTION
|
||
The TZ environment variable tells functions such as the ctime(3) family
|
||
and programs like date what the time zone and daylight saving rule is.
|
||
The value of TZ has the POSIX standardized form shown in the synopsis.
|
||
This form specifies the zone names, offsets from GMT, and daylight
|
||
savings changeover times for at least the current year.
|
||
|
||
zone A three or more letter name for the time zone in normal (winter)
|
||
time.
|
||
|
||
[-]offset
|
||
A signed time telling the offset of the time zone westwards from
|
||
Greenwich. The time has the form hh[:mm[:ss]] with a one of two
|
||
digit hour, and optional two digit minutes and seconds.
|
||
|
||
dst The name of the time zone when daylight savings is in effect. It
|
||
may be followed by an offset telling how big the clock correction is
|
||
other than the default of 1 hour.
|
||
|
||
start/time,end/time
|
||
Specifies the start and end of the daylight savings period. The
|
||
start and end fields indicate on what day the changeover occurs.
|
||
They must be in one of the following formats:
|
||
|
||
Jn The Julian day n (1 <= n <= 365) ignoring leap days, i.e. there
|
||
is no February 29.
|
||
|
||
n The zero-based Julian day (0 <= n <= 365). Leap days are not
|
||
ignored.
|
||
|
||
Mm.n.d
|
||
This indicates month m, the n-th occurrence of day d (1 <= m <=
|
||
12, 1 <= n <= 5, 0 <= d <= 6, 0=Sunday). The 5-th occurrence
|
||
means the last occurrence of that day in a month. So M4.1.0 is
|
||
the first Sunday in April, M9.5.0 is the last Sunday in
|
||
September.
|
||
|
||
The time field indicates the time the changeover occurs on the given
|
||
day.
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
1
|
||
|
||
|
||
|
||
TZ(5) Minix Programmer's Manual TZ(5)
|
||
|
||
|
||
EXAMPLES
|
||
Greenwich Mean Time:
|
||
|
||
TZ=GMT0
|
||
|
||
Middle European Time, 1 hour east from Greenwich, daylight savings starts
|
||
on the last Sunday in March at 2 AM and ends on the last Sunday in
|
||
October at 3 AM:
|
||
|
||
TZ='MET-1MET DST,M3.5.0/2,M10.5.0/3'
|
||
|
||
British time, daylight savings starts and ends at the same moment as MET,
|
||
but in an earlier time zone:
|
||
|
||
TZ=GMT0BST,M3.5.0/1,M10.5.0/2
|
||
|
||
The eastern european time zones also have the changeovers at the same
|
||
absolute time as British time and MET.
|
||
|
||
U.S. Eastern Standard Time, 5 hours west from Greenwich, daylight savings
|
||
starts on the first Sunday in April at 2 AM and ends on the last Sunday
|
||
in October at 2 AM:
|
||
|
||
TZ=EST5EDT,M4.1.0/2,M10.5.0/2
|
||
|
||
It shouldn't surprise you that daylight savings in New Zealand is
|
||
observed in the months opposite from the previous examples. It starts on
|
||
the first Sunday in October at 2 AM and ends on the third Sunday in March
|
||
at 3 AM:
|
||
|
||
TZ=NZST-12NZDT,M10.1.0/2,M3.3.0/3
|
||
|
||
SEE ALSO
|
||
readclock(8), date(1).
|
||
|
||
BUGS
|
||
You may have noticed that many fields are optional. Do no omit them,
|
||
because the defaults are bogus. If you need daylight savings then fully
|
||
specify the changeovers.
|
||
|
||
West is negative, east is positive, ask any sailor.
|
||
|
||
AUTHOR
|
||
Kees J. Bot (kjb@cs.vu.nl)
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
2
|
||
|