iPhone 15 clock is 3 minutes fast

Hi Soggyshoe, to fix your iPhone being a few minutes ahead of the actual time, you can fix this in two different ways;

First you want to head to settings, then go to Date & Time, you then select “Set Automatically” to on (if it isn’t on), if that doesn’t work you can disable it and set the time to the correct time by looking below “Timezone” and selecting the time it displays and changing that to the proper time.

You can see this Apple Support Article for more details:

Change the date and time on iPhone - Apple Support

hello have you set the time to automatic?

seetting->general->date&time and toggle automatic