Double Sync Calendar Pad:

December 2015:

January 2016

L0.00 = exact sync
L0.01 = sync within 1 minute
L0.03 = sync within 2 minutes
L0.05 = sync within 3 minutes
L0.07 = sync within 4 minutes
L0.09 = sync within 5 minutes
L0.15 = sync within 10 minutes
L0.25 = sync within 15 minutes
L0.5 = sync within 30 min
L1 = sync within 1 hour
L2 = sync within 2 hours