Change time winter=>summer

UNIX AIX
1

Hi!

I have forgotten to change the file /etc/environment on a server.
I had this ligne for TZ variable

TZ=NFT-1DFT,M3.4.0/2:00:00,M10.5.0/2:00:00

So, yesterday I had the wrong date

Yesterday I changed the hour to come back at the good hour and change /etc/environment by this lign

TZ=NFT-1DFT,M3.5.0/2:00:00,M10.4.0/2:00:00

This morning when I came back, I was at H-1

Do you have a explanation?
thx!

2

yes, ... M3.4.0 ... meant change DST value on fourth Sunday of March (which was last week) and ... M3.5.0 ... means change on fifth Sunday of March - which is 31 March this year.
When there are not 5 Sundays, the change is made on the fourth Sunday.

3

I changed it again yesterday. I don't have the error anymore.
I cross the fingers for the next weekend.

Thanks

4

The time on your system has never changed (that is an internal number).
To see how it looks to new users either login again, or type

$ date
  • modify TZ variable using set - or edit /etc/environment. If you edit /etc/environment, then
. /etc/environment
$ date

The last command gives the new presentation. Do not use the date command to change the time itself, just use the TZ variable to change the presentation of time of day.