As you know, the lowercase letters s and i correspond to the second and the minute respectively, both zero-padded, however, unlike hour, these do not have not zero-padding number equivalents, I suggest assigning to the S the not zero-padded second, and, if it's not too much trouble, replace the functionality of the I with the not zero-padded minute, and assign that other functionality to the letter E, if not possible, then assign to E the minute with not zero-padding, although it would not be so coherent.
