What unlocks it
Endless Mode is unlocked by formally clearing Pingzhou Night Market. Entering it at all is its own achievement. In-game, the mode's own Chinese name — 长夜收摊, literally "closing up shop through the long night" — is what the achievement list uses throughout.
What the store page says
"Clear the main markets, then take on Endless Mode: rents keep climbing, the market keeps shifting — armed with everything you've built, how many days can your little jade stall survive?"
Confirmed day-count milestones
| Days survived | Achievement |
|---|---|
| 15 | "Open for Half a Month Straight" / 半月不打烊 |
| 25 (voluntary stop) | "The High-Risk Proprietor" / 险料掌柜 |
| 30 | "The Monthly Report Outlasts You" / 月报比人长 |
| 40 (voluntary stop) | "Alone With the Lamp, Watching the Market" / 孤灯守市 |
| 60 (voluntary stop) | "The Jade Lamp Never Dims" / 玉灯长明 |
Three of these five (25 / 40 / 60) specifically require voluntarily ending the run at or after that day, implying the mode can also end involuntarily — likely from running out of cash against rising rent.
Unconfirmed
The exact rent-escalation formula, whether there's a hard cap on survivable days, and what carries over from main-mode progress into Endless Mode are not documented anywhere official yet.