first you should controll the date and time on your raspberyy pi, not only the TimeZone.
You should download your calender and control, if the Dates are correctly stored there or if is there a time difference.
When everything is right, I cannot help you.

which time and date shows your raspberry pi ?

@sacha81 thats no problem. Export your large an old calender on your PC. Create a new calender an import the data. Delete all the data in your main calender and import the small calender, sort by my Python Skript. So you got one calender with your old data and one small with your 2017 datas.

Hello everybody. I come with very good News ! I find a solution without the people from MagicMirror.

1. My old google calendar was too big (850k) and I search earlier for a solution to delete my old calendar entries in the google calendar, e.g. everything before 2017, but there were no function or button at google.
2. I export my old and heavy ics File from google to my Computer.
3. I wrote a short python script, which takes the ics header from my ics file, delete everything that is older than 2017 and ended with the original ending from my ics file. The new file is 85k :)
4. I create an test calender to import the ics file - everything is ok.
5. I delete every !! entrie in my Maincalender (my heart goes up) and import the new light ics file - everything goes fine and the new calendar is shown in the MM calendar.
6. Delete the test calender
   Another nice thing is, that there are now no old datas in the google calender. For further information, just contact me.
   Yours
   Peter

Hello everybody - I know now, that the problem with the google calendar is. As sacha81 wrote : a small calender will be displayed, a big one ( my is 850k) not !! I tested it with a new calendar with 10 entrys. Is there a way to get the old version back ? The calendar is for me the most important item in the magic mirror. Nobody needs a buggy version of MagicMirror.

@strawberry-3.141 what do you think is the second instance of MM ? There’s only one who listen on 8080 and when I kill this app, my MM close.

and before I install the Update of MM, everything works fine.

Thank for your help but I think there is no other Application who listen on 8080. This is the result on your idea and I think electron.js is an app of MagicMirror isn’t it ?

Hello yawns,

this are the Terminal messages after i follow your advice. I log into over ssh.

Hello yawns,
the url is a google calendar ics url and when I paste the url in my browser it load.
This are the error Messages after i type npm start dev.