"The" epoch

• Just means the starting date and time for a calendar
• Gregorian epoch is 0001-01-01 00:00:00
• Unix epoch is 1970-01-01 00:00:00 UTC
• Other OS's vary
• Perl's time() uses the OS-native epoch
• On many OS's, the epoch is a 32-bit signed int
• Unix epochs can range from 1901-12-13 to 2038-01-19