It takes little time, more prep work than anything, and the finished result should have you smiling.
Designs take a bit more time, but worth it. All over floor painting can go pretty quick.
Start with an enamel paint. Depending on the color you choose, you may need to apply more than one coat of paint. Allow the freshly painted floor to dry completely, usually 24 hours is recommended and then apply 3 to 4 coats of varnish. If you want a shiny floor like the picture above you will need to apply a high gloss varnish. If you prefer a more satin finish then you need to cover with a satin or matte varnish.
After you've applied the varnish, allow to dry for another 24 hours.
Place a fan on the completed floor to speed up the process.
Painting old wood floor white is one of my favorites.
If done correctly, they will last for many years to come.