The date of birth of my ID card is 19940802. Is it 18 years old according to the lunar calendar or the new calendar?

I don't know whether you are from the countryside or the city.

In the past, the countryside was not so strict, and birth certificates were generally written according to the lunar calendar. If it's official, it's all written according to the solar calendar, which is the new calendar you mentioned.

If both your household registration book and your ID card are filled in the lunar calendar, then all places that need to fill in the date of birth must be filled in the lunar calendar in the future, which is consistent with the ID card household registration book, otherwise it will be very troublesome in the future.

It is worth noting that although you write it in the lunar calendar, that is, you know it is your birthday, most people bring it here, or you will become a great man and celebrity in the future. When you look at the date in your account, you will think it is the date of the solar calendar (although this date is actually your birthday in the lunar calendar), understand?