Question. There are now four weeks remaining until may 20th which is my set-out date. Daylight will be ~14 hours so in order to progressively reduce light exposure from 24 hours to 14 hours by then I should be giving it ~20 min less light a day.
( 24 hrs - 14 hrs = 10 hrs = 600 min / 28 days = ~21 min / day )
I have it in the middle of a garage so it's not light isolated right now but could this be as simple as getting a light proof black sheet, switching the lights off and covering it for 20 min more each day?