On Linux, plan your task for hour, minute, second accuracy

There is cronno second accuracy planning in the standard , since

• Unix server administration traditionally rarely requires one-second accuracy.
• , " "

sleep(1) GNU Coreutils .

: 12:14:05 12:14:10

$ crontab -l
(snip...)
14 12 * * * sleep 5; date > /tmp/plain.txt
14 12 * * * while [ "1410" -gt "$(date +\%M\%S)" ]; do /bin/sleep 0.1; done; date > /tmp/while.txt

( ...)

$ ls -l --time-style=full-iso /tmp/*.txt
-rw-r--r-- 1 nodakai nodakai 43 2014-02-22 12:14:06.236151567 +0800 /tmp/plain.txt
-rw-r--r-- 1 nodakai nodakai 43 2014-02-22 12:14:10.007600677 +0800 /tmp/while.txt

1- , 14 12 crontab 12:14:00 sharp. while sleep(1) .

, , NTP , .