Cistercian numerals are really good for writing date/time stamps.
Here’s an example datestamp for the date of this post:
Each single character can hold four decimal digits, meaning one character for the year, one character for the month and day, one character for the hour and minute. You could add a fourth character for to account for time down to the 100th of a second, but this is not typically needed in practice.
I keep an index card of the numerals in my journal to remember which is which, although at this point I don’t need to reference it any more.
I’ve also made use of this digitally. On the Disquisition research page, I use Cistercian numerals to show the dates of each post, and include a checkbox for a decimal date label for them.
You can do the same on any Hugo site, including with the decimal date annotations, by using my hugo-theme-cistercian utility theme.