To check what is missing in the Five Elements Birth Test, you can use the following methods: 1. Online: There are some birthdate and horoscope query services provided online. You can enter your date and time of birth on these. The system will calculate the missing five elements based on your birth date. 2. Manual calculation: You can manually calculate your birth date based on the lunar calendar and birth time, refer to the horoscope book or other related information, and then determine the missing five elements based on the distribution of the five elements in the horoscope. No matter which method is used, it is recommended to refer to multiple sources for comparison and verification to get more accurate results.