I upgraded but bookable objects - something wrong properties disapeared when i want to book it i get error 500 something with timezone

in calendars in objects details i have strange formats in prices and dates SoAMUTCE_wrzesień+0000RWrzAMUTC_6+0000RWrzAM1calendarerase

i get such error from frontend:
DateTime::__construct() [datetime.--construct]: Failed to parse time string (PnAMGMTE_maj+0000RMajAMGMT_0+000017) at position 0 (P): The timezone could not be found in the database

Ok, because you probably need to solve it for the weekend, I think you can set date formats in Configuration -> General -> Date Format -> set Use Custom
If you set there new formats, I think it should work. See how to set format in this link: http://php.net/manual/en/function.strftime.php

Can you also check logs if there is anything else about error 500?

If Custom formats will not help, you can try to reinstall the component once again, or check rights on translation files in language.
We were not able to simulate your problem with dates, but there were some other people what posted us these problems. I think they solved it somehow, but I don't know how at the moment. I will try to take a look on forum topics and let you know if I find something.

EDIT: But you can try uninstallation and new installation. Maybe it was not installed correctly for first time.

ok i will try what with missing properties . After upgrade a few properties disapeared is ti normal?

i can not even go to calendar when i click reserve on object i get 500 error
www.radek.kdweb.eu/index.php?option=com_...m%20Tenisowe%20Arena

with date construct error