Coupon - Trials with selector for months/quarters/years

Currently in Coupons, a Trial can only be set for X Days.

In Offers, Trials have the ability to set for X Days, Months, Quarters, Years. 

Could we please have this same selector in Coupons so I can have a coupon give a "2 Month Trial". Today I can only set it to "60 Day Trial" which is not exactly 2 months.