Might be a bug:

If i have unused swap sitting at 30 days and then use up a tiny bit (say to pay off interest) the rest of the swap's expiry is reduced by a *full day*. So my previously 30 day swap after being touched is now a 29 day swap. then if it's touched again it gets reduced to a 28 day swap. and so on. This is all happening on the same day, so it's not like i'm rolling over time legitimately. A day is taken off the swap time whenever the swap is cut but not completely used.

Can this be fixed?