How long does the flu last in a room?

I have the flu, or something. It’s not COVID, but I have a fever, some congestion, coughing. Feels like the flu to me.

My wife is away. When she was around, I was quarantining myself in the office and guest room, and wearing a mask for my forays to other parts of the house. She comes back tomorrow afternoon. When do I need to start masking up and quarantining again?

Mr. Google thinks the answer is 24 to 48 hours.

Cites from the Mayo Clinic and the NIH tend to agree, so it looks like Mr. Google isn’t a bad source in this particular case.

Yesterday, apparently.

Oh well. I guess I’ll start now. What a pain.

The critical point that you didn’t mention is when did your symptoms , like a fever, first start?

The started last on Saturday and come on strong on Sunday. Today (Thursday) was the first day I woke up without a fever.

So you were probably most infectious last Thursday evening & Friday, before your symptoms started.
And it usually lasts 10 days, so by Monday you should be mostly over it. (Just in time to go to work!)

Well, thankfully, no one I know got it from me! Nice having something as non-infectious(!) as the flu instead of COVID.