Epoch
A reference point in time used as the origin for a particular time measurement system.
In timekeeping, an epoch is a reference point in time used as the origin for a particular time measurement system. Different systems use different epochs as their starting points.
Some notable epochs include:
1. Unix Epoch: January 1, 1970, 00:00:00 UTC - Used for Unix timestamps 2. GPS Epoch: January 6, 1980, 00:00:00 UTC - Starting point for GPS time 3. J2000 Epoch: January 1, 2000, 12:00:00 TT - Standard reference epoch in astronomy 4. Windows Epoch: January 1, 1601, 00:00:00 UTC - Used in NTFS file systems 5. NTP Epoch: January 1, 1900, 00:00:00 UTC - Used in Network Time Protocol
Epochs are chosen for various practical or historical reasons. When working with different time systems, it's important to be aware of their respective epochs to correctly convert between them.