What are the abbreviations for days of the week? [closed]
Solution 1:
Three-letter abbreviations are more common, but two-letter ones are also fully understandable.
In a tabular calendar, even one-letter abbreviations are acceptable, since the position is sufficient to disambiguate the S's and T's.
Solution 2:
Another variation I have seen (and used) is (starting with Sunday): Su, M, Tu, W, Th, F, Sa
In other words, single letters for unambiguous days, two letters for the ambiguous ones.