In everyday messaging, “t.s” sometimes shows up as a trimmed version of a longer phrase. People may also use it stylistically—like they do with “idk,” “brb,” or “imo”—even when it isn’t a widely standardized abbreviation.
That means “t.s” in a chat could be personal jargon, a group-specific nickname, or shorthand for something the sender has already defined. In other words, it might not mean the same thing for two different people.
If you’re dealing with a message you didn’t write, try looking for clues: what did the sender say right before and right after “t.s”? If the sentence reads like a normal phrase with a missing word, “t.s” could stand for a short label or a common term within that conversation.