Can I find out who sent the message via WeChat Time?

No.

The information sent by Time and Space Communication cannot be detected by the other party, so it is safe. The message of time is anonymous, and the anonymous letter you received from the message of time and space is true. When sending a letter anonymously, the other party does not know who wrote it, and the content of the letter cannot be made public, which achieves the effect of anonymity very well. WeChat’s messaging assistant is anonymous.