This is inflexibility:
A so called "Early Report Day" (day off BEFORE the actual trip) is required if cabin crew has to report before 8 AM. The only trip in the network which actually gives this is a two day trip to TLV (Tel Aviv). The flight is around four and a half hours one way and includes a 24 hour stop in Tel Aviv followed by three local nights in London. The crew usually also gets at least a 20 minute break each way.