Plan it in great detail before you start, including pipe runs and reflooring. Provide agreed drawings which include positioning and heights in advance. Doing the drawings will prompt questions so you can deal with them before work starts.
If you are not living in the house, an extra day or two doesn't matter so much.
There is plumbing and wiring under the floor. I like a new floor in square-edged WBP ply panels in a bathroom, screwed down, so that you can take up sections easily and without damage. This may need a joiner who can also do the architrave and skirting, and windowboards if you have them. I prefer the new flooring to be down before the new sanitaryware so it can stand on top with no Vandyking. If you have another bathroom you can remove the old stuff in advance and refloor at your leisure.
Have all the materials ready in the room next to the bathroom, and it helps if you are able to go to a merchant quickly when you need extras.
In my own house, I had all plumbing and sanitaryware ripped out and refitted in two days (excl redec or tiling). I put in wall lights and shaver socket and patched the plaster at the end of day 1 after the plumber and his lad went home. Otherwise you would need to arrange plasterer and electrician separately. Fittings and especially bath must remain covered until all work is finished to prevent anything falling in (grit, rubble, tools) and damaging them
Tiling seems to take just over 1 day.
I suppose if you had to arrange all trades separately you would be lucky to finish in a week. Builders are usually quite bad at scheduling trades, which are usually subcontracted.
Have plenty of rubble sacks, dustpan and brush, and a canister vac. Don't allow anyone to use your household vac for builders dust and rubble. Get cotton dustsheets to protect carpets on the route. Keep all other doors shut to reduce dust migration.
A builders idea of clean may not be the same as yours.