Part of the lack of timetable is it's not queenlessness that leads to laying workers, it's broodlessness. If the hive loses a queen, there is still open brood for the next 9 days or so. If the hive has no brood from the start, then it will go laying worker sooner. So if a package loses a queen in transit or before she lays, it will end up with laying workers sooner than if a hive with open brood loses a queen. Usually from the time I lose a queen to laying workers seems like about three weeks. But 9 days of that there was open brood. So 21 - 9 would be about 12 days of broodlessness to end up with laying workers from my observation. Sometimes less.