http://wkki2ufbs7lbd7li3bpomaiwdqu67dblfg3auoldksaqrgrlcz252lqd.onion/faq.html
An input of "3mo" would mean 3 months and "1y2mo3w4d5h6m7s" would mean 1 year, 2 months, 3 weeks, 4 days, 5 hours, 6 minutes and 7 seconds. Units of time should be in descending order, so "2w1mo" is invalid.
However you may use "6w" for example to input 6 weeks, and are not required to use "1mo2w".