supporting before current support effort is up

If I decide to support before my current support time runs out does it:

A) the support time runs concurrently with my current support effort

Example: current support efforts are 1/01 to 6/30 support again in 3/01 total support time runs to 8/31

Or

B) the support time is appended

Example: current support efforts are 1/01 to 6/30 support again in 3/01 support time runs 7/1 to 12/31

Thanks,

Gerald

The latter, Gerald.
I added another year a couple months back,
even though my support was good through March.
There is no overlap.
Linton