Experience drain at login is based on when you last logged off the game.
You will drain a percentage of your field experience up to the maximum of 100% (8 hours).
To give you an idea of how it will break down:
30 Minutes - 6.25%
2 Hours - 25%
4 Hours - 50%
8 Hours - 100%
Key points to note:
1) Players who have received a warning within the last 6 months will not drain experience at login. This rule is very similar to that which is applied to thump when a warning is received.
2) You must be logged out for at least 30 minutes to drain experience when you log back in.
Discuss it here!