Tag Heuer Carrera CV2A10 date display changes at 3AM??

Unfortunately, there is not much you can do with this, as for fixing it you need very experienced watch repairers help. All I can do is just name all possible reasons why it happened. FIRST reason could be: the day wheel somehow has lifted and not sitting in correct position. This would be the easiest fault for watchmaker to repair, as only dismantling the movement, correcting the day wheel and re-assembling will be necessary, so, no serious repairs needed. SECOND reason can be: the star, which is friction fitted to the day wheel is getting loose. In this case, if watchmaker will not be able to fix the day wheel, you will have to buy new day wheel + all work previously explained. THIRD reason: the day wheel click spring is weak/bent/broke. In this case you have to buy new day wheel click spring + again all the work previously explained. FOURTH and last reason: day wheel positioning screws/borders became loose. In this case only the work explained in FIRST reason will be necessary. If you are so lucky and still have warranty for your watch - send it back to Tag Heuer and they will do repairs without charge, because this fault is covered by warranty. If warranty has expired, you do not need to find any particular Tag Heuer watch repair shop. As all watch movements are manufactured on identical basic principles, any reputable/decent watchmaker will do the job for you. Prepare yourself to pay quite a lot, because Tags are expensive to deal with and takes a lot of time and skill to fix. This is all help I can give. Wish you luck. Rate me, please, and/or write some testimonial if you have spare minute.