When I sync to strava some activities do not display as the correct time I did them in. outdoor run and bike are fine but not all others which appear as half a day before.

This is a bug in Strava. By default, certain activities (for me it's the ones I manually enter) are set to the default time zone which is in Europe. 

To fix this, you have to log into the Strava.com website, either on your phone or another device. It's not currently possible to change this in the Strava app. 

In your account on Strava.com, change your time zone to match your location. Save it, and this bug should be fixed for future uploads.