What is the difference between UTC and local time?¶

UTC is a global reference; local time is civil time for a place and date. Their offset depends on jurisdiction and daylight-saving rules rather than one fixed conversion.

Systems may store and display differently¶

A device can store local time while a cloud platform stores UTC and converts for the viewer. In the UK, GMT matches UTC while BST is UTC plus one hour. Other locations change on different dates or not at all, and historical rules vary.

Convert by named zone and date¶

Establish whether every value is UTC, local or explicit offset and retain suffixes such as Z, +00:00 and +01:00. Use the correct named zone and event date and record original and converted values.

Do not infer physical location from a device's configured zone; settings can be manual or retained after travel.