Not a good idea. Modern "Stains" are really varnish with tint. Varnish takes a good long time to dry therefore stain takes a good long time to dry. Polyurethane is also a type of varnish. Putting that over a layer of varnish that hasn't completely dried is not at all a good idea.
Lots of dependencies...
Size of the floor to be done;
Humidity of the environment (impacts drying time);
Availability of appropriate tools;
Skill/experience the people doing the work;
The stain and polyurethane drying intervals specified by the manufacturer...
For all we know, it is a small 2 feet x 2 feet place where there is no furniture and a big sander won't fit, so sanding needs to be done by hand and the humidity is 99%... or it could be a 200 foot by 500 foot wood floor and a crew of people will be doing the work, but first a LOT of furniture needs to be moved and stored, 5 sanding machines will be used and humidity is 30%... but the specified stain drying time is 10 hours.