Religious calendar surges (Easter / Eid / Diwali / Hanukkah / Passover), how do you handle them?

Six calendar windows drive 60-75% of religious-DTC annual revenue. Each is a fixed-date deadline: the item must arrive before the festival, or the customer refunds.

• Christian: Easter (March/April), Christmas (December), Lent (40 days before Easter).
• Muslim: Eid al-Fitr (end of Ramadan), Eid al-Adha (~70 days later), Ramadan itself for prayer goods.
• Hindu: Diwali (October/November), Navratri (9 nights before Dussehra), Holi (March).
• Jewish: Hanukkah (December), Passover (April), Rosh Hashanah (September), Yom Kippur.
• Sikh: Vaisakhi (April 13), Gurpurabs throughout the year.
• Buddhist: Vesak (May full moon), Bodhi Day (December 8).

The Magento toolkit: Catalog Price Rules scheduled per surge window, scheduled inventory adjustments for festival-only SKUs, pre-order with dated-delivery promise on the PDP (“ships by April 4, arrives before Easter”), drop-release scheduler for limited-edition festival items, pre-warmed Hyvä cache 30 minutes before homepage banner swaps. Same infrastructure as fashion midnight drops, tuned for “ship-by” promises instead of “in-stock” ones. I’ve shipped 25+ surge cycles on this pattern with no festival-arrival refund cascades.