Minimum time:
All modes have a minimum delay time of 5 milliseconds.
Maximum time:
Almost all the modes have a tap and knob time.
The maximum tap time for non-multitap modes is 2.5 seconds. Keep in mind that the ratio applies after this - so if you used the the max ratio of 1.67:1 (tied quarter note triplet) it would be 4.175 seconds
The maximum delay time you can set with the knob is 1.2 seconds. We picked this range because the avg person wants 100-400ms delays, and they're hard to dial in if the knob range is huge.
For multitap modes, the maximum tap time (for any of the multi-taps) is 2.0 seconds.
The maximum time of the special long delay mode (ambient yellow) is 8.0 seconds. It multiplies your tap time by 4 to get the delay time.
If you want the color from a tape mode, but need a really long delay, you can always set the routing to serial and send the tape mode (with a really fast delay time) into the long delay mode to achieve a really long tape delay mode.