Things now uses a single input field for entering due dates. It accepts many different formats such as 12/25/07, 12-25-07, 12.25.07, or Dec 25th, 2007. System wide preferences for the ordering of date components are honored.
You do not need to specify day, month, and year at once. Numbers greater than 1000, or constructs such as '08 are interpreted as years. 1st, 2nd, 3rd, 4th, etc. are taken to mean days. Ambiguities are resolved by assuming the users preferred ordering. Non existing components assume default values.
Dates can also be specified using relative expressions like, “today”, “tomorrow”, or “in 1 week”. “2 weeks”, “3 months”, “next year”, or short variants like “4d”, “2w” work also. Weekday names can be used like in “Mon next week”, or “Tue in 2 weeks”. Words like “in” are optional and short versions for day, week, month, and year can be used here as well. A single weekday name like "Wednesday" will always denote the next Wednesday. If you enter “Wednesday” on a Thursday, Wednesday next week will be assumed.
Currently, the situation for users of languages other than English or German is not ideal. Names for weekdays and months are automatically translated by Mac OS, since we are using Mac OS’s date preferences. Words like “today, tomorrow, day(s), weeks(s), month(s), year(s)” and also short versions like “d, w, m, y” cannot be handled by Mac OS. Those need to be translated manually. If you like to have those words translated to your language as well, just send us an email with the relevant translations, and we will be happy to have them included in the next update.