I have a Bulova chime mantle clock, three wind, that needs sync. it is off by 15 minutes (it chimes 1/2 hour on 15 minute time etc. can you help me?

The next time it chimes multiple times turn the hour hand clockwise until it is pointing at the number of times it gonged. Next take off the dial nut off (make sure to put it in a plastic bag because they can be hard to replace) and turn the minute hand until it chimes signaling 15 minutes after. Now put the minute hand back on pointing to 3 o'clock and replace your dial nut and you are all set. Fix Clock That Gongs Wrong

Simplest way is to remove the minute hand on dial and reseat it at the correct setting I.e one quarter turn .recheck the hour chime is on hour etc.replace glass front.