How to set the first of the week to be Sunday in the Calendar that is displayed in the System Tray of Windows Vista Home Basic. I tried setting the first day of the week to Sunday in Windows Calendar (thinking that it might work) and yet still it displays the first day of the week to be Monday. Moreover there are not settings available on the System Tray Calendar

7 Answers 7


Using regedit, browse to HKCU\Control Panel\International, look for the iFirstDayOfWeek key and set the value to 0 for Monday, 1 for Tuesday, 2 for Wednesday, etc ...

  • 4
    for users with windows 8.1, the correct path is HKEY_CURRENT_USER\Control Panel\International. Also to open registory editor, press start button + r simultaneously and type regedit .
    – Nishant
    Commented Jan 15, 2015 at 13:51
  • For users of Windows 10, @Nishant's comment still holds.
    – Kuba
    Commented Aug 16, 2017 at 15:07

On Windows 10:

  • Right-click on the Taskbar Clock area. Choose Adjust date/time

  • It opens a dialog, with a Formats section, where there is a display-only summary of options, including First day of week. Click the link Change date and time Formats

  • On the dialog that now appears, you can choose what one you want on the First day of week combobox.


I ran into this exact issue when getting issued a UK-regioned desktop.

You need to go to Control Panel -> Regional and Language Settings and pick a region that starts the week on Sunday, like US.

  • 3
    To add to this: In Windows 7 this is an independent setting and can be found on the "Date" tab when customizing the locale.
    – Joey
    Commented Oct 27, 2009 at 7:40
  • good to know - I haven't had a chance to futz with Win7 yet :)
    – warren
    Commented Oct 27, 2009 at 7:43
  • and the downvote on this answer is because ...?
    – warren
    Commented Oct 8, 2014 at 16:14

Just go Regional and Language Settings, there is a combo box: "First day of week:", and you know what to do next...

  • 1
    Hard to understand why this was downvoted. It's a reasonable solution, though maybe not the best one. Commented Nov 23, 2012 at 3:56
  • 1
    very easy: there is no option like that in Windows Vista. Commented Oct 7, 2014 at 22:43
  • If you are on windows 10, here are steps :
    1. Right click on the date and time area on the taskbar
    2. click on properties
    3. in the setting screen, on the upper right hand corner, there will be a search box, type : first
    4. You will see the option change the date and time format. Click On that.
    5. on the next screen, first option will be to change the first day of the week.

Reg script

Adding to user8228's answer:

Create a .reg file with the following content:

Windows Registry Editor Version 5.00

[hkey_current_user\control panel\international]


; the change is immediate

Either click on it to be imported using graphical confirmation dialog, or use reg import *.reg command to do the same from the command-line.


  • case doesn't matter except in the first line
  • REG_SZ (string) type is indicated by quotes ("0")
  • double quotes are mandatory as single quotes won't work
  • reg command is the reg.exe executable in %windir%\system32
  • ; is for adding comments (commenting the line) within the reg file

By default, windows will show Sunday to Saturday... if you want to change it to Monday to Sunday follow these steps.

Step-1 Open control panel (Windows button+X, Select control panel (P))

Step-2 In Clock, Language and Region select Change date, time, or number format

Step-3 In formats tab go to the first day of week select Monday (or whatever the day you would like to start your week)

Step-4 Press Apply and OK.

Now check your system calendar. it's done :)

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