Question

I’m a bit lost with time terminology.

I understand what epoch is and the difference between GMT and UTC.

However I’m a bit confused about the following notations:

• calendar time
• local time
• wall time

How are these related to timezones and daylight savings?

P.S.
Good link (thanks to @ZincX)

Answer 1

• Calendar time is the time that has elapsed since the epoch (t – E).
• Local time is calendar time corrected for the timezone and DST.
• Wall time: I assume you mean wallclock time. This it the time elapsed since a process or job has started running.

RTFM time(7), localtime(3), time(1).