When do sold listings drop from monthly limit?

[collect-em_all]

Do sold listings stop counting toward listing limit in one of these ways? If so, which?

1 month AFTER the item was listed
Ex. Listed Jan 9th (sold some time that month), drops from listing limit count on Feb 9th

1 month AFTER sale
Ex. Item sold Jan 9th, drops from listing limit count on Feb 9th.

Or, on the 1st of each month?
Ex... One Item listed & sold Jan 1st, and another listed & sold Jan 25th will both stop counting toward listing limit on Feb 1st.

I ask, because I started a store around 1 month ago, and am at my 500 limit. However, I was hoping some items that sold this time last month would start dropping off my limit counter. I only have around 190 active listings (~400 items), and having the sold ones counting toward my limit is really hindering growth.

[pjcdn2005]

To be honest I don't know what happens in that case.  I suspect that it will renew anyway but I'm just guessing.  Hopefully someone else knows the answer to that.