Behid the question was my, obviously incorrect, assumption that olde visual studio versions, from times when c++20 was not yet conceived and epoch thus not set to Jan 1 AD 1970, are using some different epoch - as Microsoft frequently did, like Jan 1 AD 1 (.NET), Jan 1 AD 1601 (NTFS),
Jan 1 AD 1980 (DOS, FAT family of file systems). So seeing Microsoft embracing a standard thing like posix epoch without screaming and kicking is a nice surprise.