This article describes a hotfix that updates daylight saving time (DST) settings for Mexico, Mongolia, and Iran. This update supersedes KB 3039024. Before you install this hotfix, check the Prerequisites section in this article.
MexicoA new time zone, “Eastern Standard Time (Mexico),” was added in KB 3039024. It was originally set to observe DST from the first Sunday of April through the last Sunday of October. However, according to the latest announcement from the Mexican government, this time zone does not observe DST. Therefore, the previous DST rules for this time zone are removed in this update.
MongoliaMongolia will observe DST starting this year. DST for Mongolia starts on the last Saturday of March at 02:00 and ends on the last Saturday of September at 00:00. The following DST rules will be observed.
|Time zone key name||Display name||DST start||DST end|
|Mongolia Standard Time||(UTC+8:00) Ulaanbaatar||Last Saturday of March at 02:00:00.000||Last Saturday of September at 00:00:00.000|
IranIran follows the Persian calendar. This update corrects the DST data for "Iran Standard Time" in Windows for the years 2015 through 2024.
Hotfix informationThis hotfix applies to the following operating systems:
- Windows Server 2012 R2
- Windows 8.1
- Windows RT 8.1
- Windows Server 2012
- Windows 8
- Windows RT
- Windows Server 2008 R2 Service Pack 1 (SP1)
- Windows 7 SP1
- Windows Server 2008 Service Pack 2 (SP2)
- Windows Vista SP2
- Windows Server 2003 SP2
- Windows XP Embedded
How to obtain this hotfixA supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.
If the hotfix is available for download, there is a "Hotfix Download Available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website: Note The "Hotfix Download Available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.