How to use time of birth as a tag

How to use time as a tag?for example, I want to make a query based on the time of birth,or there are better ways to deal with it .thanks~

In your use case do you have multiple data points with the same time of birth? I’m trying to understand why you want to make time a tag value. Generally, for InfluxDB, you can store time as a timestamp and you can query the database limiting results (using WHERE or GROUP BY()) based on the time interval passed in.