TZ environment variable

Specifies the mapping from the universal reference time to local time.

The TZ environment variable is typically specified in the ars.cfg file, and can also be specified as an ENVAR LE runtime option in the PARM= value in the ARSSOCKD STC.

The ars.cfg contains this TZ value: TZ=EST5EDT

The value of the TZ environment variable has the following fields:
standard
An alphabetic abbreviation for the local standard time zone. For example: GMT, EST, MSEZ.
HH[:MM[:SS]]
The time offset westwards from the universal reference time. 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 daylight is specified without a daylight offset, daylight savings time is assumed to be one hour ahead of the standard time.

[daylight]
The abbreviation for your local daylight savings time zone. If the daylight field is missing, Daylight Saving Time conversion is disabled. The number of hours, minutes, and seconds your local Daylight Savings Time is offset from UTC when Daylight Savings Time is in effect. If the Daylight Savings Time abbreviation 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 Savings Time, specifying when Daylight Savings Time should be in effect. Both the startdate and enddate must be present, and must either take the form Jn, n, or Mm.n.d..
  • Jn is the Julian day n (1 <= n <=365) and does not account for leap days.
  • n is the zero-based Julian day (0 <= n <= 365). Leap days are counted; therefore, you can refer to February 29th.
  • 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 might 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 Savings Time rule is omitted altogether, the values in the rule default to the standard American Daylight Savings Time rules starting at 02:00:00 the first Sunday in April and ending at 02:00:00 the last Sunday in October.

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