Kids are different from adults when they haven't got the concept of clock time. They ask when their friend is coming over and the answer is "in two hours" or "at 2 o'clock". At young ages, that means little and the child can't read the clock face to see how much progress has been made toward the desired time. Some lessons in elementary school are aimed at helping the pupils gained clock reading ability. With digital clock faces, there is an additional type of learning needed.
We saw an early clock in a bell tower in England. It was a device to strike the massive bell on the hour with the number of hits equal to the hour. That was it, no graphic representation or figures of any sort. No information on parts of an hour or of minutes or of seconds. I guess they had little need then for such time details.
I have trouble telling time without any clock or watch. Daylight and dark help some. I read that the setting sun can be read to estimate how much time until sunset by holding one's hand up to the space between it and the sun and estimating 15 minutes per finger of sky in the gap.
Calendars seem both simpler and subtler than clocks. I see in movies and books how a prisoner starts to mark off days on the cell wall to keep track of time. I can completely believe in the need to do that. I can sit down with a pad and quickly make a calendar as far into the future as I want with a pencil and something to make a straight line. I can't make a clock or a timer that easily. But as I get older, the calendar seems more important and clocks and watches less so.
I was surprised when I switched from Outlook to Gmail at how much I missed the calendar. Google does have a calendar and I have set it up partially. Still, as with any new interface, it takes some getting used to. When both people work, a couple may have a relatively simple schedule most days. When they are retired and their options increase, each person's calendar can get much more complex. Starting the day with a look at the calendar events posted for it helps avoid missing something. Looking ahead a day or a week helps get gifts and cards purchased in a timely way. Being able to share access to each other's calendars helps in knowing when a doctor's appointment or car repair is coming up.
When I realized that the adults in the family have calendars as well as memorized birthdays in their heads, I thought it might help my great grandson to have a year's calendar with family birthdays and major holidays on it. I doubt if he has made it a regular part of his life yet but he will someday. Calendars have a place in all our lives.
