English: Time zones are regions that share the same standard time. Most zones are defined by their offset from UTC. Some countries also observe daylight saving time (DST), which can temporarily change offsets.
中文： 时区是采用统一标准时间的地区。大多数时区用与 UTC 的偏移来表示（如 UTC+8）。部分地区会实行夏令时（DST），这会在一年中的某些时间段改变时差。