The dates are represented in a confusing format where the month is put before the day and the year. As the day was larger than 12, I could deduce that this was the correct date, however a date like 01.03.2022 would be ambiguous. My expectation would be that either a ISO format is used, or perhaps this could be selected as a configuration.
Click on a chat.
Go to Members section.
Observe a chat member that has not read the chat for more than a day.
Telegram Web 1.51.1 Z, Chrome 104