If you are doing this for only part of the year, one thing to be aware of is the Hawthorne Effect [0]. We're wired to seek novelty, and you may see a temporary increase in productivity each time you change working hours because of this. It's actually a reasonable argument for changing things around periodically, as long as it doesn't happen too often. (Note, however, that the effect may be limited to actual experiments where you're making careful observations. There isn't good consensus on it.)

[0] https://en.wikipedia.org/wiki/Hawthorne_effect