Shelf life of a post?

I occasionally use but read it often and I haven’t noticed any announcements regarding a shelf life of an advert. I placed an advertisement for a teacher some time ago ( I suppose somewhere in April) and by May it has gone. Please inform if there’s any definite time job ads will be removed.

It’s 30 days. This is posted in some of the forums but not the Jobs forums it seems. I’ll correct that.