Why Japan rejected DST

The 1948–1952 DST experiment was imposed by the post-war Allied occupation, and almost everyone in Japan disliked it. Farmers complained about hotter morning fieldwork; office workers complained about longer evening commutes; schools complained that early mornings were pitch dark. When the occupation ended in 1952, Japan dropped the practice within months. Periodically since then — the 2018 push around the Tokyo Olympics was the most recent — proposals to reintroduce DST for energy savings have come up in the Diet. Each time the measure has failed or been withdrawn. JST is rock-solid.

The salaryman workday and its limits

The stereotype of Japanese corporate culture — 9am arrival, 10pm departure, overtime on top — is real enough that the government has spent a decade trying to regulate it down. Large Tokyo employers now typically run 9am–6pm with mandatory "lights-out" at 8pm in the newer buildings. But the practical reality for anyone scheduling calls: a request for 9am Tokyo is fine, 10pm Tokyo is marginal, and anything after 11pm JST will get a polite no. Early morning is a better ask than late evening, and 8am JST is perfectly acceptable.

The 14-hour gap to the US East Coast

JST sits 14 hours ahead of EST and 13 hours ahead of EDT. The only sane synchronous window between Tokyo and New York is 6–8pm ET on a weekday, which equals 7–9am JST the next morning — near the edge of both workdays. For LA, the gap is 17 hours in winter and 16 in summer, which is actually a bit easier to plan: 4pm PT on Monday equals 9am JST on Tuesday, a clean morning-to-morning handoff across the international date line. London to Tokyo is 9 hours (8 in BST), with a narrow window between 8 and 10am GMT that catches afternoon Tokyo.