topic Re: Time Change in Operating System - HP-UX

Time Change

Sana Chaarani — Fri, 04 Apr 2003 16:00:58 GMT

OK.. thanks for the answers..
but how come in the tztab man page i have the following table:

0 3 1-7 4 1987-2038 0 EDT4

It does say 0 (mn ) 3 (hour) though !!
Am i understanding it wrong ?

Thanks again !

Re: Time Change

Pete Randall — Fri, 04 Apr 2003 16:15:00 GMT

From the man page:

Normally (as indicated in the first line) Eastern Standard Time is
five hours earlier than UTC. During Daylight Savings time, it changes
to a 4 hour difference. The first time Daylight Savings Time took
effect (second line) was on January 6, 1974 at 3:00 a.m., EDT. Note
that the minute before was 1:59 a.m., EST. The change back to
standard time took effect (sixth line) on the last Sunday in November
of the same year. At that point, the time went from 1:59 a.m. EDT to
1:00 a.m. EST. The transition to Daylight Savings Time since then
has gone from the last Sunday in February (third line) to the last
Sunday in April (fourth line) to the first Sunday in April (fifth
line). The return to standard time for the same period has remained
at the last Sunday in October (seventh line).

Pete

Re: Time Change

Pete Randall — Fri, 04 Apr 2003 16:16:49 GMT

Oops should have included the referenced lines:

EST5EDT
0 3 6 1 1974 0-6 EDT4
0 3 22-28 2 1975 0 EDT4
0 3 24-30 4 1976-1986 0 EDT4
0 3 1-7 4 1987-2038 0 EDT4
0 1 24-30 11 1974 0 EST5
0 1 25-31 10 1975-2038 0 EST5

Pete

Re: Time Change

Adam J Markiewicz — Fri, 04 Apr 2003 17:13:43 GMT

Hi

My fault.

tztab is the definition of everything.
THe moment of timechange did vary across the years, so thats why so many entries (you can check that in either timezone you have proper definitions from 1970 to 2038 anyway).

1970 is the moment when the computers were born. ;)
2038 is the moment when their internal counters (counting every second from 1970 in 32bits) will overflow. I think that will be the End of the World. ;)

Returning to the main topic:
You understand correct.
Just assign the TZ and the rest of magic will be done by the system automatically.

To make it permanent adjust /etc/TIMEZONE file (once more in your case it should be set to EST5EDT)

Good luck
Adam