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

If you have used classic Outlook for years, you may have accumulated custom holiday files with a .hol extension. These files let you import your own set of holidays into the calendar, such as company-specific days or regional observances not included by default. In new Outlook for Windows, the way holidays are managed has changed. This article explains what .hol files are, why they no longer work in new Outlook, and what to do with them today.

The .hol file format is a legacy text-based structure that classic Outlook reads to add holiday entries to your calendar. New Outlook uses a different calendar data model and does not support importing .hol files directly. You will need to convert your holiday data or use alternative methods to get the same result. This article covers three practical options: converting the .hol file to a CSV import, manually creating a calendar for recurring events, or switching back to classic Outlook if you need the original feature.

By the end of this article, you will know exactly how to handle your existing .hol files and keep your custom holidays in new Outlook without losing any data.

What Are .hol Files and Why They Stopped Working

A .hol file is a plain text file that contains a list of holiday dates and their names. Classic Outlook reads this file and adds each date as an all-day event on your calendar. The file format is simple: each line starts with a date in the format YYYY/MM/DD, followed by a tab character, then the holiday name. For example:

2025/01/01 New Year's Day

Classic Outlook stored these files in a specific folder and allowed you to add or remove holiday sets through File > Options > Calendar > Add Holidays. New Outlook does not include this dialog or any method to read .hol files. The underlying calendar system in new Outlook is built on Exchange Online and Microsoft Graph, which do not support the legacy .hol import mechanism.

Where Your .hol Files Are Located

If you have used custom .hol files in classic Outlook, they are typically stored in one of these locations:

• %ProgramFiles%\Microsoft Office\root\Office16\1033\Holidays\ — for built-in holiday files
• %AppData%\Microsoft\Holidays\ — for custom holiday files you created or downloaded

You can open the .hol file with Notepad to see the list of dates and names. This is useful for the conversion steps below.

Option 1: Convert .hol to CSV and Import to New Outlook

The most direct way to preserve your custom holidays in new Outlook is to convert the .hol file to a CSV file and import it as calendar events. This method works for one-time imports. If your holidays change each year, you will need to update the CSV manually.

1. Open the .hol file in Notepad
   Right-click the .hol file and select Open with > Notepad. You will see lines like 2025/12/25 Christmas Day.
2. Copy the data into a spreadsheet
   Open Excel or Google Sheets. Paste the data. The date and name will appear in two columns. Adjust the date format to MM/DD/YYYY if needed, as new Outlook expects that format during import.
3. Save as CSV file
   In Excel, go to File > Save As and choose CSV UTF-8 or CSV (Comma delimited). Name the file Holidays.csv.
4. Open new Outlook calendar
   Launch new Outlook. Select the Calendar icon at the bottom of the navigation pane. Choose the calendar where you want the holidays to appear, or create a new calendar by right-clicking My calendars and selecting Add calendar > Create blank calendar.
5. Import the CSV file
   In new Outlook, click File > Open & Export > Import/Export. Select Import from CSV and choose your Holidays.csv file. Map the Date column to Start Date and the Name column to Subject. Set the duration to 1 day. Complete the import.

After import, each holiday appears as an all-day event. For recurring yearly holidays, you will need to edit each event and set the recurrence pattern to yearly. This is time-consuming if you have many holidays. Consider Option 2 instead for recurring events.

Option 2: Create a Dedicated Holiday Calendar with Recurring Events

If your .hol file contains holidays that repeat every year on the same date, you can create a separate calendar in new Outlook and add each holiday as a recurring yearly event. This method keeps your holidays separate from your main calendar and makes them easy to toggle on or off.

1. Create a new calendar
   In new Outlook, go to Calendar. In the left pane, right-click My calendars and choose Add calendar > Create blank calendar. Name it Custom Holidays.
2. Add the first holiday as a recurring event
   Click New Event at the top. Enter the holiday name as the title. Set the date to the first occurrence. Set the time to All day. Click the Recurrence dropdown and select Yearly. Choose Every year on the same date. Click Save.
3. Repeat for each holiday
   For each line in your .hol file, create a new event with the same recurrence settings. If the holiday falls on a specific day of the month, select the correct yearly recurrence pattern.
4. Toggle the calendar visibility
   In the calendar pane, uncheck the Custom Holidays calendar to hide all holidays at once. Check it again to show them.

This option requires manual entry but gives you full control over recurrence and visibility. You can also share this calendar with other people if needed.

Option 3: Switch Back to Classic Outlook

If you rely heavily on .hol files and the conversion process is too complex, you can switch back to classic Outlook. Microsoft allows you to toggle between new Outlook and classic Outlook at any time. Classic Outlook still supports .hol files and the Add Holidays dialog.

1. Open classic Outlook
   In new Outlook, click the File tab and select Options. Under the General section, find the toggle that says New Outlook. Turn it off. Outlook will restart in classic mode.
2. Import your .hol file
   In classic Outlook, go to File > Options > Calendar > Add Holidays. Click Browse to locate your .hol file. Select the file and click Open. Check the box next to the holiday set name and click OK. The holidays appear on your calendar.
3. Toggle back to new Outlook when ready
   You can switch back to new Outlook at any time by turning the New Outlook toggle back on. Your imported holidays will not transfer, but they remain in classic Outlook.

Limitations and Things to Avoid

New Outlook Does Not Support .hol Files at All

Do not expect Microsoft to add .hol import support to new Outlook. The feature is not on the roadmap. Plan to migrate your holiday data using one of the methods above.

CSV Import Does Not Support Recurrence

When you import a CSV file, each row becomes a single event. There is no way to set recurrence during import. You must edit each event afterward to make it recurring. For yearly holidays, Option 2 is more efficient.

Do Not Delete Your .hol File Until You Confirm the Import

Keep the original .hol file on your computer until you have verified that all holidays appear correctly in new Outlook. If something goes wrong, you can start over.

New Outlook Custom Holiday Options: Comparison

Item	CSV Import	Recurring Calendar
Setup effort	Moderate — requires conversion and editing	High — manual entry for each holiday
Recurrence support	No — must edit events after import	Yes — set yearly recurrence per event
Best for	One-time dates or non-recurring holidays	Yearly holidays that repeat on the same date
Visibility toggle	Events appear in the target calendar	Separate calendar can be shown or hidden

Your .hol files are not useless. You can extract the data and use it in new Outlook through CSV import or a dedicated recurring calendar. If neither method works for your workflow, classic Outlook remains available. Choose the method that matches how often your holidays repeat and how much manual work you are willing to do.

To make future updates easier, consider storing your holiday list in a spreadsheet or a shared calendar that you can update once per year. Use the Ctrl+Shift+2 shortcut in new Outlook to switch to Calendar view quickly. If you manage team holidays, share the Custom Holidays calendar with colleagues so everyone stays on the same schedule.