Python or Bash commands to determine time since a cron job string would have triggered
I'm writing a Django app (although parts can be Bash) that stores the cron job strings of many other machines. It needs to calculate the amount of time since that cron job would have triggered on that machine. Is there a python library useful for converting cron style strings to another Python friendly scheduler format that has a function for determining when that should have last triggered?
For example: a machine has a cron job at "0 8 * * 1-5" (every weekday at 8am local time to that server). Assuming my Django app was in the same time zone, and the current time was 10:15 AM on a Tuesday, then my app would need to be able to calculate 2 hours and 15 minutes as the answer.