Linux task schedule to Hour, minute, second

Question

I'm trying to run a shell script at a specific time up to it's seconds (H:M:S) , but so far all programs such as at only go up to a specific minute (not second).
I don't want to use sleep since it's not accurate. For some reason it ended couple of hours earlier than it was supposed to!

Answer 1

Your question doesn't seem to define accuracy, but there is always some jitter in scheduling in electronic devices. You might use quartz to schedule to the second. You could also use at or cron to schedule to the minute and then sleep the appropriate number of second(s).