How to set crontab a 12pm (night) everyday?

Question

Please provide entry..

Log file generated on the basis of dates..

Answer 1

0 0 * * *  

0 0 * * * your_command_goes_here
| | | | |
| | | | +- every year
| | | +--- every month
| | +----- every day
| +------- 0th hour of the day.[hour = 0 ]
+--------- Top of the hour [minutes = 0].

The interpretation of cron expression may differ from the implementation here it is for the linux cron .
If you didn't expecting it then be specific.

Answer 2

0 0 * * * your_command_goes_here

is how you do it. Midnight is basically 00:00 and the date you get from date will be the new date, not the old.

If you want the older date, just start at 11:59, get the date straight away, then sleep for 61 seconds:

59 23 * * * your_command_with_a_60_second_delay_goes_here

That's probably easier than trying to worry about date calculations. I'm nothing if not sneaky :-)