When it says כל הלילה (all of the night) – sometimes it means all of the night literally and sometimes it means part of the night (so when it really means “all of the night”, it is necessary to add כל הלילה עד הבוקר - all of the night until the morning). And the rule in this is that if the emphasis of the expression and its new information is about the start time or that it does not stop in the meantime – possibly it is referring to the start time and it is necessary to clarifyעד הבקר (until the morning).