Command format

Format

TZ= standardHH[:MM[:SS]] [daylight[HH[:MM[:SS:]]] [,startdate[/starttime],enddate[/endtime]] ]

Description

All commands assume that times stored in the file system and returned by the operating system are stored by using Coordinated Universal Time, hereafter referred to as the universal reference time. The mapping from the universal reference time to local time is specified by the TZ (time zone) environment variable.

The value of the TZ environment variable has these fields (two required and three optional):
standard
An alphabetic abbreviation for the local standard time zone; for example, GMT, EST, MSEZ.
HH[:MM[:SS]]
Start of changeIndicates the value that is added to the local time to arrive at Coordinated Universal Time.End of change A leading minus sign (-) means that the local time zone is east of the universal reference time. An offset of this form must follow standard and can also optionally follow daylight. An optional colon (:) separates hours from optional minutes and seconds.

If daylightdaylight is specified without a daylight offset, Daylight Saving Time is assumed to be one hour ahead of the standard time.

Start of changeFor more information about setting time zones, see tzset() — Set the time zone in z/OS C/C++ Runtime Library Reference.End of change

[daylight]
The abbreviation for your local Daylight Saving Time zone. If the daylight field is missing, the conversion to Daylight Saving Time is disabled. The number of hours, minutes, and seconds your local Daylight Saving Time is offset from Coordinated Universal Time when Daylight Saving Time is in effect. If the abbreviation for Daylight Saving Time is specified, and the offset omitted, the offset of one hour is assumed.
[,startdate[/starttime],enddate[/endtime]]
A rule that identifies the start and end of Daylight Saving Time, specifying when it should be in effect. Both the startdate and enddate must be present, and must either take the form Jn, n, or Mm.w.d..
  • Jn is the Julian day n (1 <= n <=365). Leap days are not counted. In all years, including leap years, February 28 is day 59 and March 1 is day 60. It is impossible to implicitly refer to the occasional February 29.
  • n is the zero-based Julian day (0 <= n <= 365). Leap days are counted, and it is possible to refer to February 29.
    For nonleap years:
    • January 1 (Day 0)
    • February 28 (Day 58)
    • March 1 (Day 59)
    • December 1 (Day 364)
    For leap years:
    • January 1 (Day 0)
    • February 29 (Day 59)
    • March 1 (Day 60)
    • December 1 (Day 365)
  • Mm.w.d defines the day (0 <= d <= 6) of week w (1 <= w <= 5) of month m (1 <= 12) of the year. Week 5 has the last day (d) in month m, which may occur in either the fourth or fifth week). Week 1 is the first week in which the dth day occurs. Day zero is Sunday.

Neither starttime nor endtime are required. If they are omitted, their values default to 02:00:00. If this Daylight Saving Time rule is omitted altogether, the values in the rule default to the standard rules for American Daylight Saving Time.

When the TZ variable is not set, time conversions behave as if TZ were set to TZ=GMT0.

Portability

This interpretation of the TZ environment variable is a superset of that supported by UNIX System V.

Reference

The locale, date, and touch commands.