Not that it's important, but I believe it's 48 hours, and 8 hours if you haven't entered your passcode in the last six days. You also only get five tries, so a finger that is sometimes recognized but not with great reliability would still probably fail.
• Not unlocked for 8 hours after not having used passcode for 6 days
• Not unlocked for 48 hours otherwise
• Restarted
• 5 failed fingerprints
• Enrolling new fingerprints
If the OS handles it (and potentially if the OS files themselves aren't completely and fully encrypted) then you can trick the OS into thinking it hasn't been 24-48 hours - all you need is for the fingerprint TPM to keep returning 'success'. If the TPM handles it then it is slightly harder to do.