[sf-lug] at teatime, etc.

[Michael Paoli]

Ah yes, I might've responded more tersely with:
at(1)
... in any case, at(1), cron[d]/crontab, batch, et. seq. quite handy,
... most commonly:
at for future one-shots
batch for (about) now ... or when the load permits (and detached, etc.
like at), and
crontab - for repeated regular scheduling.

Some other differences to note:
if the system is down when the event would have run, with at, the scheduled
events are started in the proper order when the system is up.  With crontab,
they're skipped (see also anacron).  at/batch vs. crontab also have
different behaviors regarding environment and the like.

at teatime is likely a GNU and/or Vixie cron extention ... might be handy,
but not a most portable, or standards compliant construct ... but noon and
midnight likely are, as they go way back into rather to quite early UNIX at(1)

references/excerpts:
news:53vqk9$ebh at crl6.crl.com
> Date: Mon, 2 Jun 2008 20:56:33 -0700
> From: Rick Moen <rick at linuxmafia.com>
> Subject: Re: [sf-lug] email to my future self
> To: sf-lug at linuxmafia.com
> 
> at, batch, atq, and atrm are all related utilities -- which please see.
> All of them deal with the queue of requests for "atd" the "at daemon".
> 
> My favourite aspect of "at" is that it is able to parse "at teatime"
> (4pm), in addition to "at midnight" and "at noon".