For Gregorian calendars, the date format varies from a country to another. There are three main formats recognized:
Your task is to write a program which, given an input string representing a date, output all the possible date formats by which this string can be interpreted as a date.
- The input date is in the format
xx-xx-xx, where each field is two digits and zero-padded.
- The date is always valid (so you cannot get things like 14-13-17)
- The date is always at least one of the formats above (so you cannot get things like 17-14-11)
- Because we are in fact in a parallel world, there are 31 days for every month of the year, and consequently no leap years
- The date is between January 01, 2001 and December 31, 2099
- If there is only one format for the date, the code must print only it (only trailing newlines are allowed)
- If there are several formats for the date, they must be either separated by a comma, a space, a newline, or a combination of those
- You must output the exact name(s) of the format(s). Using distinct arbitrary values is not allowed.
- No leading or trailing characters others than a trailing space are allowed
- The output must be lowercase
- You are not allowed to use any built-in date or calendar functions
- The output formats do not have to be sorted
30-05-17 big-endian, little-endian
12-11-31 big-endian, little-endian, middle-endian
This is code-golf so the shortest code in bytes wins. Explanations are encouraged.