How to convert UTC time to local time

INTRODUCTION

Microsoft uses Coordinated Universal Time (UTC) format, an international standard 24-hour timekeeping system, to document the created dates and times of files that are included in a software update. This article describes how to convert UTC to local time to verify that the file that is on your computer is the one that is discussed in the documentation.

More Information

To convert UTC to local time, follow these steps:

1. Determine your local time offset from UTC time. To do this, follow these steps on a Microsoft Windows-based computer:

   1. Click Start, click Run, type timedate.cpl, and then click OK.

   2. Click the Time Zone tab, and then verify that your local time zone is selected. If your local time zone is not selected, click it in the list of available time zones.
      
      The local time offset is shown at the start of each local region list item. For example, -5:00 is the local time offset for Eastern Time (US & Canada):

      (GMT-5:00) Eastern Time (US & Canada)

2. Add the local time offset to the UTC time.
   
   For example, if your local time offset is -5:00, and if the UTC time is shown as 11:00, add -5 to 11. The time setting when adjusted for offset is 06:00 (6:00 A.M.).
   
   Note The date also follows UTC format. For example, if your local time offset is -8:00, and if the file's UTC time is shown as 00:00 (12:00 midnight) on Monday, the adjusted time is 16:00 on Sunday (4:00 P.M., Sunday).

3. Adjust for daylight saving time.
   
   UTC time is not adjusted to reflect daylight-saving time. If your time zone participates in daylight saving time, add the time difference to the file's offset-adjusted time when daylight saving time is in effect. For example, if daylight saving time in your time zone is one hour ahead of standard time, add one hour to the offset-adjusted time.

4. Convert the 24-hour time format to 12-hour time format if your local time uses the 12-hour format. To make the conversion, follow these steps:

   • If the offset-adjusted time is between 12:01 and 23:59, inclusive, subtract 12 from the adjusted time, and then append P.M.

   • If the adjusted time is between 00:01 and 11:59, inclusive, leave the adjusted time as is, and then append A.M.

   • If the adjusted time is 00:00, use 12:00 midnight.

   • If the adjusted time is 12:00, use 12:00 noon.

Notes

• You can use this method to compare the file's converted time to the time of a software update file that is on your computer.

• When you view the file details of the file that is on your computer, the date in the Date Modified column may be different from the date in the Date Created column. If this difference occurs, use the date in the Date Modified column.