Halloween, then St Patrick’s Day. Both are single evenings rather than seasons, so nothing is salvageable if the order misses the date. Leave the widest margin you can on these two.

The first half of November. Late November and December are the heaviest carrier weeks of the year, and every piece is made after you order, so production time sits on top of transit.

Because the date moves each year. People work backwards from where it fell last time and lose a week or more. Check the actual date first, then count back.

These are gift dates rather than wear-it-yourself dates. Specificity beats theme — a team or a hobby lands better than a generic seasonal design. For Mother’s Day, non-clothing items in Home & Living outsell apparel.

Pride pieces, because they are worn across June and at events all summer rather than on a single date. Costume-style designs tied to one evening get the least wear.

Loud or joke-led designs. These are worn to mark something rather than to get a laugh, so restraint reads better than volume here than at any other date on the calendar.

Full coverage from 3D Clothing for costume-style single evenings. Panel prints from 2D Clothing for gatherings and gifts, since those get worn again afterwards.