Classic Outlook to New Outlook: Custom Holiday Files – What to do with .hol files today

If you have used Classic Outlook for years, you likely have a .hol file containing custom holidays you created or imported. This file stores dates for holidays that Outlook adds to your calendar automatically. The new Outlook for Windows does not support .hol files at all. This article explains what .hol files are, why the new Outlook ignores them, and how to move your custom holidays into the new Outlook so you do not lose them.

What a .hol file is and why the new Outlook cannot use it

A .hol file is a plain-text file that contains holiday data in a specific format. Each line lists a holiday name and its date. Classic Outlook reads this file when you click File > Options > Calendar > Add Holidays. The file can be the default holiday set that ships with Outlook or a custom file you created or downloaded from a third party.

The new Outlook for Windows is a completely different application from Classic Outlook. It does not share the same add-in architecture, file format support, or calendar import pipeline. The new Outlook uses Exchange Online or Outlook.com as its primary data store and relies on modern calendar sync methods. Because .hol is a legacy file format that was never ported to the new codebase, the new Outlook simply ignores .hol files. There is no import button, no drag-and-drop support, and no hidden setting to load them.

If you switch from Classic Outlook to the new Outlook, your existing .hol file remains on your computer. The file is not deleted. But the holidays it contains will not appear on your calendar unless you take manual steps to import them.

How to locate your custom .hol file

Before you can convert or move your holidays, you need to find the .hol file. Classic Outlook stores holiday files in a known folder. The exact path depends on your Outlook version and whether you installed Outlook from Microsoft 365 or a volume license.

The most common location is:

C:\Program Files\Microsoft Office\root\Office16\Holidays\1033

The folder name “1033” is the locale ID for English (United States). If you use a different language, the folder number changes. For example, 1036 is French (France) and 2057 is English (United Kingdom).

If you installed Outlook via the Microsoft Store or a volume license, the path may be:

C:\Program Files (x86)\Microsoft Office\root\Office16\Holidays\1033

Custom .hol files are sometimes saved in the same folder or in a user-created folder. If you cannot find your file, search your entire C drive for hol using Windows File Explorer.

Steps to convert a .hol file to .ics and import it into the new Outlook

The new Outlook can import calendar events from .ics files. You must convert your .hol file to .ics format. There are two methods: manual conversion using a script or automatic conversion using a PowerShell script. Both methods produce the same result.

Method 1: Manual conversion using a text editor and a script

1. Open the .hol file in Notepad
   Right-click the .hol file and select Open with > Notepad. You will see lines such as “New Year’s Day,20250101”. Each line has a holiday name and a date in YYYYMMDD format.
2. Copy the content to a new text file
   Press Ctrl+A to select all text, then Ctrl+C to copy. Open a new Notepad document and paste the content.
3. Save the file as .hol.txt
   Click File > Save As. Change the “Save as type” dropdown to “All Files”. Name the file holidays.txt and save it on your desktop. This step is optional but helps avoid confusion.
4. Use a conversion script
   You can use a free online converter or a local PowerShell script. For a local script, open Notepad and paste the following code:

   $holidays = Get-Content -Path “C:\path\to\your\holidays.txt”
   $ics = @”
   BEGIN:VCALENDAR
   VERSION:2.0
   PRODID:-//Manual Conversion//EN
   “@
   foreach ($line in $holidays) {
     $parts = $line.Split(‘,’);
     $name = $parts[0];
     $date = $parts[1];
     $year = $date.Substring(0,4);
     $month = $date.Substring(4,2);
     $day = $date.Substring(6,2);
     $dtstart = “$year$($month)$($day)”;
     $ics += “`nBEGIN:VEVENT`nDTSTART;VALUE=DATE:$dtstart`nSUMMARY:$name`nTRANSP:TRANSPARENT`nEND:VEVENT`n”
   }
   $ics += “`nEND:VCALENDAR”
   $ics | Out-File -FilePath “C:\path\to\output\holidays.ics” -Encoding UTF8

   Replace the input and output paths with your actual file locations. Save the file as Convert-Holidays.ps1. Right-click the file and select “Run with PowerShell”.

5. Import the .ics file into the new Outlook
   Open the new Outlook. Click File > Open & Export > Import/Export. Select “Import an iCalendar (.ics) file” and click Next. Browse to the holidays.ics file you created and click OK. The new Outlook creates a new calendar named “holidays” and adds all events to it.

Method 2: Use a third-party .hol to .ics converter

1. Search for a .hol to .ics converter online
   Several free web tools accept a .hol file and return an .ics download. Use a tool that runs entirely in your browser to avoid uploading sensitive data to a server.
2. Upload your .hol file
   Follow the tool’s instructions to select your .hol file. The tool parses the file and generates an .ics file.
3. Download the .ics file
   Save the .ics file to your desktop.
4. Import the .ics file into the new Outlook
   Use the same import steps as in Method 1: File > Open & Export > Import/Export > Import an iCalendar (.ics) file.

What happens to the original .hol file after migration

The .hol file remains on your computer even after you import the .ics file into the new Outlook. You can keep it as a backup. If you ever switch back to Classic Outlook, you can use the .hol file again. Deleting the .hol file has no effect on the new Outlook because the new Outlook does not reference it.

If you want to remove the .hol file to save space or clean up old files, you can delete it manually. The file is typically small, under 100 KB, so the space savings are negligible.

If you cannot locate your .hol file

If you cannot find your .hol file, check whether you still have Classic Outlook installed. Open Classic Outlook and click File > Options > Calendar > Add Holidays. The dialog shows which .hol files are currently loaded. The file path appears in the title bar of the Add Holidays dialog. You can also click Browse to locate the file.

If you no longer have Classic Outlook installed, search your entire computer for hol using File Explorer. If no .hol file exists, you may need to recreate your holiday list from scratch. Use a spreadsheet to list each holiday name and its date, then export the spreadsheet as an .ics file and import it into the new Outlook.

Item	.hol file	.ics file
File format	Plain text with name,date pairs	iCalendar standard with VEVENT blocks
Supported by Classic Outlook	Yes, via File > Options > Calendar > Add Holidays	Yes, via File > Open & Export > Import/Export
Supported by new Outlook	No	Yes, via File > Open & Export > Import/Export
Recurring events	Not supported natively	Supported with RRULE
Editing	Notepad or text editor	Any calendar app or text editor

The new Outlook for Windows does not support .hol files. To keep your custom holidays, you must convert the .hol file to .ics and import it. After importing, the holidays appear on a separate calendar that you can rename or merge with your main calendar. For recurring holidays that repeat every year, consider setting up a yearly recurrence rule in the new Outlook instead of importing single-date events.

If you manage holidays for a team, store the .ics file on a shared network drive or SharePoint site so others can import the same set of holidays. The new Outlook does not have a shared holiday file mechanism, but an .ics file can be distributed and imported by anyone.

Advanced tip: Use the PowerShell script from Method 1 to generate an .ics file that marks events as “transparent” (free time). This prevents holidays from showing as busy time in your calendar. The script in Method 1 already includes the TRANSP:TRANSPARENT property.