If you live in a urban area with many outside lights or your child’s room is on the bright side of the house during naptime, you may want to consider a blackout curtain.
You can make one yourself by purchasing the curtain at a fabric store for around $10. Cut tiny holes every few feet and install grommets in the holes. This will keep the holes from tearing out.
Then attach some eyehooks above the window and use some glue in the holes to keep them in place. You can also glue some weights to the bottom if the curtain doesn’t hang flush against the window.
Once you have your curtain, you can hang it up as needed. Plus your child will think you are awesome for making the sun set on cue. 😉