I’m unaware of a documented list, but I find that OmniFocus is good at understanding pretty much anything I throw at it.
Here are some examples to add to the list:
0d – today 3h – three hours from now -1d – yesterday 1w – one week from now 1m – one month from now 1m 3d – 1 month and three days for now 28 – 28th day of the current month mon – next Monday fri 1w – 1 week from Friday fri 1w 21: – 1 week from Friday at 21:00 (9pm)
I really struggle to stop myself from typing “this evening”, but maybe I can retrain myself to use some of these. Unless of course the OmniFolks feel like expanding the support.
Just to give a bit more detail on the ones I mentioned: today – 00:00 (midnight) on the current day tomorrow – 00:00 (midnight) on the next day tonight – 23:00 (11pm) on the current day next week – 00:00 (midnight) on Sunday. Not “next week” if you think of the week starting on a Monday, but hey-ho! next month – 00:00 (midnight) on the first day of the next month. next year – 00:00 (midnight) on the first day of the next year. Use this to create your resolutions? 😉
There are some additional options that may be less useful… yesterday last week last month last year this year
It’s worth noting that the default time for tomorrow, next week, etc. are dependent on the Date & Time Preferences. For example, if I specify a defer date of “tomorrow” (or “1d”), OmniFocus will use tomorrow’s date at 3:00 am. Similarly, the default due time in my case is 4:00 pm.
On a side note, these preferences sync across devices. For example, if I specify a default defer time on my Mac, it will also apply to OmniFocus on the iPhone, iPad, and Web.