Hello Pheannuecoo99
You are probably talking about a 5-days Swiss Travel Pass (not SwissPass).
If it is a consecutive pass, its validity will start on 23 Feb, until 28 Feb at 5:00 AM.
If it is a flex pass, you can start using it on the 25th, after having activated the first day of validity at activateyourpass.com
Kind regards,
Roland