Time in EFI

[Fernando Boza]

How I can modify the hour of the EFI and that does not change whenever it reinitiates the equipment?

[Phil uk]

Hi,

You should be able to set the time in EFI with the time command:

time [hh:mm[:ss]]

(Accepts 24hr format)

Regards,
Phil

[Fernando Boza]

I believe the time zone is wrong set.

[Phil uk]

Hi,

I dont think that I have seen anything in relation to Timezone in EFI.
Can I ask by how many hours it is wrong....and are you in the Netherlands?

I have heard that they are set to GMT, but i might be wrong.
Phil

[Fernando Boza]

I'm from Ecuador.
The time from MP always have 5 hours more.

[Matti_Kurkela]

That's because EFI shows the raw hardware clock time, which is in UTC timezone ("universal time") - as it should be in any Unix system. The difference between UTC and Ecuador's ECT time is exactly 5 hours.

UTC time does not observe Daylight Saving Time, so a timestamp that is expressed in terms of UTC is never ambiguous. The operating system has a set of rules to convert time between the UTC time and the local time of any configured time zone.

All Unix-like operating systems convert all time values internally to UTC timezone, and then convert them back to the local timezone for display.

MK

[Fernando Boza]

That means that I cannot set the hour of the EFI as I want?

[Matti_Kurkela · Accepted solution]

Well, technically, you *can*, but it has some very unwanted consequences.

First, if you set the EFI clock to local time, you must lie to the operating system and say that your timezone is equal to UTC.

This will cause trouble with many things, for example: the "Date:" headers of any email sent out from your system will have a date in them, and when converted from your pseudo-UTC to local time at the destination system, it will seem that your mail has travelled 5 hours back in time. This is a strong indication of junk email (trying to look like the *newest* message in the recipient's in-box), so you don't want that.

Second, and probably more important, is that you cannot use NTP to synchronize your system clock if you lie about your time zone. The NTP protocol is built around UTC time and that cannot be easily changed. If you try to use NTP with a fake timezone, your server's clock will seem to warp 5 hours into the future... because NTP will eventually force your system to the *true* UTC.

In practice, only the sysadmin can ever see the "raw" EFI time. It's simply not worth the effort to try to make it use the local time.

MK

[Fernando Boza]

Thanks. It's clear to me.