Birthday date ... According to QQ information, the lunar birthday is February 18 ... So when should the birthday be every year?

Gregorian calendar = Gregorian calendar-General.

Lunar calendar = lunar calendar-(domestic calendar) is used by people in China, but it is unclear in neighboring countries.

Generally speaking, people in China celebrate their birthdays according to the lunar calendar, while fortune-telling in China involves birthdays (originated from heavenly stems and earthly branches), but the lunar calendar and so on all involve heavenly stems and earthly branches. That's why fortune tellers ask when you were born.

As you said, I was born on the 2nd lunar month.18. Then you should celebrate your birthday on March 22nd this year (18 February) in the Gregorian calendar, which is 18 February in the lunar calendar. Every Gregorian calendar day has a corresponding lunar calendar day, but it changes with different years.