Time zone information and Daylight Saving Time transition rules

If you do not specify a time zone, pidiag -tz displays the time zone information and Daylight Saving Time (DST) transition rules that are being used by Data Archive. If the file PI\dat\localhost.tz is present and valid, then the time zone information is from the file. Otherwise, the information is from the operating system.

StartYear, EndYear, Month, Week, Day, Time, and Offset define the daylight and standard time transition rules.

The transition rules are:

• StartYear is the first year that the rule is in effect

• EndYear is the last year that the rule is in effect

• Month is the month (1-12) that the rule is applied.

• Week is the week (1-5) that the rule is applied. If Week is 5 and there are only four weeks in the month, then 5 designates the last week in the month. If Week is -1, then Week is ignored and day becomes absolute.

• If Week is greater than 0, then Day is the relative day (1-7) that the rule is applied. A Day of 1 represents Sunday, a Day of 2 represents Monday, and so on. For example, a Week of 1 and a Day of 1 means the first Sunday in April. If Week is -1, then Day is an absolute day (1-31).

• Time is the time in seconds after midnight that the rule is applied.

• Offset is the time in seconds to subtract from standard time to get the local time. For example, when daylight saving time is in effect, -3600 is subtracted from standard time.

If your time zone does not observe daylight saving time, the output indicates this.

C:\PI\adm> pidiag -tz

TZ environment variable: <not set>
Standard Time Name: US Mountain Standard Time (UMST)
Daylight Saving Time: <not observed>

See Customize standard and Daylight Saving Time changes to change this setting.