Problem with Dates

Hello ,
I have a strange problem with dates. When I take a date from DatePicker in Front end page it shows date as Thu May 21 2020 00:00:00 GMT+0300 (Eastern European Summer Time)

Then When I transfer the same variable to backend function and print into console same variable it shows : 2020-05-20T21:00:00.000Z
Can someone help me how to make them equal ?

Best Regards,