Mother’s Day factor
n.— «The trick is to load up the switch as much as possible, short of “blocking” or what telephone engineers refer to as “the Mother’s Day Factor.” Translation: Telephone traffic is typically highest on that day. Thus, telephone networks are designed to hold up to peak loading on Mother’s Day.» —“A Programmer’s Guide to Switched Video” by Leslie Ellis Broadcast Newsroom July 23, 2007. (source: Double-Tongued Dictionary)