Linux - check when crontab file was last amended

Question

How can i get the last updated date/time of the crontab file. not when cron was last run but instead when was the crontab file amended last

Answer 1

If you are root or sudoer:

sudo ls -l /var/spool/cron/crontabs/$USER

UPD: as pointed by @jgr, the exact path may vary, like:

sudo ls -l /var/spool/cron/$USER

Otherwise, it doesn't seem to be possible without altering directory permissions.