ICU-13845 Windows timezone detection: When DST is off, map to an Etc/GMT+-hh zone.

The Windows 'Date and Time' Control Panel has a setting for "Automatically
adjust clock for DST". When this setting is manually unchecked, the DST
setting is considered OFF, and the clock does not adjust for DST.

This change detects when the setting is OFF and uses the non-DST offset
to map to an Etc/GMT+-hh zone.

- Also refactor uprv_detectWindowsTimeZone

Co-authored-by: Jungshik Shin <>
1 file changed
tree: 620aca488e568d757f41486fe28c0f44297d61bf
  1. .appveyor.yml
  2. .ci-builds/
  3. .cpyskip.txt
  4. .gitattributes
  5. .github/
  6. .gitignore
  7. .travis.yml
  8. KEYS
  10. docs/
  11. icu4c/
  12. icu4j/
  13. tools/
  14. vendor/

International Components for Unicode

This is the repository for the International Components for Unicode. The ICU project is under the stewardship of The Unicode Consortium.

ICU Logo

Build Status (master branch)

TravisCIBuild Status
Azure PipelinesBuild Status
Azure Pipelines (Exhaustive Tests)Build Status
Azure Pipelines (Valgrind ICU4C)Build Status
AppVeyorBuild status
FuzzingFuzzing Status

Subdirectories and Information


Please see ./icu4c/LICENSE (C and J are under an identical license file.)

Copyright © 2016 and later Unicode, Inc. and others. All Rights Reserved. Unicode and the Unicode Logo are registered trademarks of Unicode, Inc. in the U.S. and other countries. Terms of Use and License