In Murder on the Nile, how long would the whole journey ideally have taken Poirot?

Basically the title. How long would it have taken the investigator from the moment he left the UK port until he set foot back in the UK?

I'm trying to figure it out, but sources aren't very clear. Especially regarding the cruise up and down the Nile. Some sources say 50 days from cairo to Luxor (don't know if it's a round trip) plus 20 days to Aswan. And I'm left wondering whether they really spent 2 months plus before he revealed the killer when they got back to cairo.