The time difference between San Juan and Shanghai is 12 hours. When it is 12:00 noon in San Juan, it is 00:00 in Shanghai. San Juan uses the America/Puerto_Rico time zone (UTC-4), while Shanghai uses Asia/Shanghai (UTC+8).
With a 12 hours gap, there is no standard business-hours overlap between San Juan and Shanghai. One party will need to adjust their schedule. Early mornings in Shanghai or late evenings in San Juan tend to be the most practical compromise.
Use this table to quickly convert any hour from San Juan time to Shanghai time. Rows highlighted in green indicate overlapping business hours in both cities.
| San Juan | Shanghai | |
|---|---|---|
| 00:00 | 12:00 | Night |
| 01:00 | 13:00 | Night |
| 02:00 | 14:00 | Night |
| 03:00 | 15:00 | Night |
| 04:00 | 16:00 | Night |
| 05:00 | 17:00 | Night |
| 06:00 | 18:00 | |
| 07:00 | 19:00 | |
| 08:00 | 20:00 | |
| 09:00 | 21:00 | |
| 10:00 | 22:00 | |
| 11:00 | 23:00 | |
| 12:00 | 00:00 (+1 day) | |
| 13:00 | 01:00 (+1 day) | |
| 14:00 | 02:00 (+1 day) | |
| 15:00 | 03:00 (+1 day) | |
| 16:00 | 04:00 (+1 day) | |
| 17:00 | 05:00 (+1 day) | |
| 18:00 | 06:00 (+1 day) | |
| 19:00 | 07:00 (+1 day) | |
| 20:00 | 08:00 (+1 day) | |
| 21:00 | 09:00 (+1 day) | |
| 22:00 | 10:00 (+1 day) | Night |
| 23:00 | 11:00 (+1 day) | Night |
Neither San Juan nor Shanghai is currently observing daylight saving time. If either city observes DST, the time difference will change by 1 hour when DST begins or ends. Always double-check before scheduling across these time zones during March–April and October–November.
The time difference is 12 hours. Shanghai is 12 hours ahead of San Juan.
It can. If either San Juan or Shanghai observes daylight saving time, the gap will shift by 1 hour during the transition periods (typically March–April and October–November).
There is no ideal window during standard business hours. Consider scheduling at the edges — early morning for the city that is ahead and late afternoon for the city that is behind.
Add 12 hours to San Juan time to get Shanghai time. Use the hour-by-hour table above for a quick reference.
For sunrise and sunset data, visit TheSunsetTimes.com. For detailed DST schedules, see DaylightSavingTime.info.