Counter example: I grew up using 12-hour time and still do to this day, with plenty of analog clocks all around, and yet I find it much easier and faster to convert between 24-hour and 12-hour time (just remove the leading 1 and subtract 2, if the hour is more than 12) than to parse an analog clock (identify which hand is which, convert the minutes to get an approximation, even more work if it's a stylized clock that might use roman numerals or not have any labels at all).
