In 1968, Long Shujin, a hard-liner who was soon to be named Communist Party secretary for Xinjiang, issued a decree ordering Uighurs to stop using their own time, according to Gardner Bovingdon, a Xinjiang expert at Indiana University who recently completed a paper on the separate time zone.
But the Chinese government was not able to enforce the law and in 1986 published a small notice acknowledging that the unofficial time could be used.
'If they really had forced people to synchronize their workdays with Beijing, it would have produced howls of protest because people would be getting up in the pitch dark," Bovingdon said.
Indeed, at 9 a.m. Beijing time on a Monday morning, when one might expect people to be bustling with the urgency of the week ahead, the city was still yawning itself awake. The statue of Mao looming over People's Square in the center of town was barely visible through a shroud of morning haze. Cars on the main road had their headlights on.
Kashgar is almost due north of New Delhi and about the same latitude as New York. Its problems with timekeeping are worse in midwinter, when the sun doesn't rise according to a Beijing-oriented clock until past 10 a.m., and during the summer solstice, when sunset is close to 11 p.m.
Unofficially, the Chinese themselves have skewed their working hours, so most schools and many businesses don't actually open until 10 a.m. Beijing time.
Jiang Lin, a student at Kashgar Teachers College, said: "Most people are using Beijing time; only local Uighurs use Xinjiang time. But our class starts two hours later than usual time. It's quite easy to adapt to it, just as when you are in Rome, do as the Romans do."
Still, Xinjiang time remains strictly unofficial. In the lobby of the Chinese-run International Hotel there are five clocks showing the time in Moscow, London, New York, Tokyo and Beijing. Asked why there was no clock indicating Xinjiang time, the concierge replied with irritation: "There's no need. They know what time it is."
Abdul Hakim, a Uighur watchmaker in the Kashgar market, said he used to stock a watch that displayed two different times, but nobody bought it.
"People use one time or the other, not both. The Chinese use Beijing time. The Uighurs use our time," he said. "But if somebody buys a watch from me, I'll set it however they like."
Nicole Liu and Eliot Gao of The Times' Beijing Bureau contributed to this report.