The rides will jump a day sometimes if the original ride was ridden in a different timezone to you. Strava works this out, but TrainingPeaks doesn’t.
To solve the problem, you can drag the session to the correct day in the TrainingPeaks Calendar.
NOTE: We work closely with TrainingPeaks to solve any issues just like this one. If you having issues with this, please contact us providing the information for your timezone and the ride you did.