Minor typo in documentation
(1) By Balaji Ramanathan (balaji) on 2021-03-17 23:02:32
In the page on "Date and Time Functions" (https://sqlite.org/lang_datefunc.html), the explanation of format strings has the following detail about the %H modifier: %H hour: 00-24 Is it supposed to be 00-23 rather than 00-24? I have tried various values of time, and different numbers of minutes and hours subtracted from them, but have never been able to get strftime to return 24 with %H. What would hour 24 even mean. I thought times in a day only go from 00:00:00 to 23:59:59. What does a time of 24:00:00 mean?
(2) By Larry Brasfield (larrybr) on 2021-03-18 00:01:53 in reply to 1 [link]
Your observation of what the doc says is correct. However, opinions may vary on whether it represents a typo or a bug. It reflects what the functions do. And what they do is arguably in line with <u>[Postel's law](https://en.wikipedia.org/wiki/Robustness_principle)</u>, which urges leniency on input and rigor on output.
As an example for discussion consider this session screen-scrape:<code>
sqlite> select datetime( julianday('2000-01-01T24:59') );
2000-01-02 00:59:00
</code>. The result is sensible, and allows somebody who may be less than utterly familiar with the 24-hour time format to speak of the earliest morning hour without mention of the zero hour. (The fact that it's in the next day is another issue; the result is logical.)
There will be no mention of hour 24 in 24-hour output from the datetime/time functions. And whether somebody exploits the input leniency is up to them.
(3) By Balaji Ramanathan (balaji) on 2021-03-21 18:30:49 in reply to 2 [link]
Ah, I see. So, allowance up to 24 is made to accommodate slightly erroneous input. I was looking at it purely from the output standpoint, and thought it was a typo in the documentation. Thank you.
(4) By Karl (kbilleter) on 2021-03-24 09:28:55 in reply to 3 [link]
According to <https://en.wikipedia.org/wiki/24-hour_clock#Midnight_00:00_and_24:00> 24 can make it clearer that your referring to midnight in the context of a day's end rather than beginning.