Seems it would be a great to see what is current time in the time zone of your chat partner. This will help a lot to not disturb people at their night time for example.
i don't think a lot of people will like this, check people activity before send message.
Or just send message muted
If a feature like this were to exist, it wouldn't be "telegram desktop" specific.
It would likely also be a setting you apply to your own account to make publically available, as not everyone would want to disclose what timezone they are from. Probably to function similar to the "last seen" visibility.
I was thinking of such a feature from quite a long time. It would help me immensely when talking across time zones and would reduce lengthy discussions regarding times and reduce misunderstandings.
Also, this can be made approximate, for example in a range of 45 minutes maybe??
I was very happy to discover that such a feature already exists in some software. Giving example from RocketChat (https://chat.inkscape.org/channel/inkscape_user)

Hey there!
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If a feature like this were to exist, it wouldn't be "telegram desktop" specific.
It would likely also be a setting you apply to your own account to make publically available, as not everyone would want to disclose what timezone they are from. Probably to function similar to the "last seen" visibility.