how to synchronize pokemon go daily bonus

Don't catch any pokemon for a full day. It's the only way unfortunately.

If you want to sync them you'll have to either not catch any mons for a day after you get the 7 day bonus for that, or not hit a pokestop the day you get the 7 day bonus for catches. But, i would recommend getting them both whenever you have the opportunity to.

The day you get your 7 day pokemon catch bonus.
Do not catch any mons on the next day, which should be the your 7 day PokeStop spin day.
Then the day after that will be day 1 for both.

I'm in the same boat and unfortunately I don't feel like missing out on my seven day bonus for PokeStops or missing out on 700 Stardust.

So I just deal with it.