Public Holidays Management for Microsoft Teams Schedule

This PowerShell script automates the management of public holidays in Microsoft Teams schedules. It fetches public holiday data from an external API and updates the designated schedule in Microsoft Teams accordingly.

• Author: Simon Jackson (@sjackson0109)
• Created: 10/02/2024
• Updated: 04/06/2024
• Thanks go to:
  • Bjoren Dassow (@dassbj01) for a hint with date.nager.at rest api service.
  • Mitchell Bakker (@mitchelljb) for his work on cleaning the schedule data set and expanding the scope into regional support.

Features

• Dynamic Holiday Retrieval: The script fetches public holiday data dynamically from an external API based on the provided country code and year.
• Schedule Update: It updates the specified Microsoft Teams schedule with the fetched public holidays, ensuring the schedule is up-to-date. TIP: Dozens of call flows (auto-attendants), can have an out-of-holidays action attached to a single schedule - giving one table of holidays to update!
• Modular Design: The code is modularized with separate functions for fetching data and updating the schedule, making it easy to maintain and reuse.

How to Use

1. Prerequisites: Ensure that you have the required PowerShell modules installed, imported and logged into the correct Tenant:

     Install-Module MicrosoftTeams
     Import-Module MicrosoftTeams
     Connect-MicrosoftTeams

2. Debugging (optional): The $DebugPreference global variable in PowerShell controls how the PowerShell runtime handles Write-Debug messages generated by scripts or cmdlets. Debug messages are useful for troubleshooting and understanding the flow of a script's execution. The DebugPreference allows users to define the behavior of PowerShell when encountering these debug messages.

   $DebugPreference = "[Option]"

   [Option] choices include

   • SilentlyContinue: Suppresses all debug messages and continues without interruption.
   • Stop: Halts execution when a debug message is encountered, allowing the user to investigate.
   • Inquire: Prompts the user to decide whether to continue or stop when a debug message is encountered.
   • Continue: Displays debug messages but continues execution without interruption. [Recommended for troubleshooting development]
   • Ignore: Ignores all debug messages and continues without interruption.

3. Import the PS1 Module: Import the PowerShell script into your environment using:

   Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope Process
   Import-Module .\TeamsPublicHolidays.ps1

   Note: One-day we will look to sign the ps1 file so the Set-ExecutionPolicy command can be skipped.

4. Execute the Script: Run the New-TeamsPublicHolidays or Update-TeamsPublicHolidays function(s) with the desired parameters to create/update the appropriate parameters; from this list:

   • ScheduleName: Specifies the name of the Microsoft Teams schedule to be updated or created.
   • CountryCode: Specifies the country code for which public holidays should be fetched. Use the country code list to find the appropriate code.
   • Year: (Optional) Specifies the year for which public holidays should be fetched. If not provided, the current year is used by default.
   • Append: (Optional) If included, the fetched holidays will be appended to the existing schedule without replacing any existing entries.

Examples

1. Create a new Schedule called UK National Holidays, specific to England only, for the year 2024, using the following:

   New-TeamsPublicHolidays -ScheduleName 'UK National Holidays' -CountryCode 'GB' -Region 'ENG'

2. Updating the existing Schedule called `DE National Holidays, use the following:

   Update-TeamsPublicHolidays -ScheduleName 'DE National Holidays' -CountryCode 'DE' -Year '2024'

3. Replace the existing Schedule called `Berlin Holidays, use the following:

   Update-TeamsPublicHolidays -ScheduleName 'Berlin Holidays' -CountryCode 'DE' -Region 'BE'

4. Update the existing Schedule called Polish National Holidays, for 2025 use the following:

   Update-TeamsPublicHolidays -ScheduleName 'Polish National Holidays' -CountryCode 'PL' -Year '2025'

5. Updating the existing Schedule called English Holidays, including England-Only holidays, for 2025 and Replace all prior dates. Use the following:

   Update-TeamsPublicHolidays -ScheduleName 'English Holidays' -CountryCode 'GB' -Region 'ENG' -Year '2025' -Replace

6. Prune an existing Schedule called UK National Holidays, removing all dates older than today. Use the following:

   Prune-TeamsPublicHolidays -ScheduleName 'UK National Holidays'

Command	Result

Where do the country codes come from?

You can look up your country code (2-digits) from here.

Where do we get the region codes from?

This is a bit of trial and error. Start by 'Printing out the holidays for the given year:

Get-PublicHolidays | ft  

Fetching holidays from URL: https://date.nager.at/api/v3/PublicHolidays/2024/GB
 - dates retrieved: 15
 - dates including global indicator: 15

Date       Name                   Global CountryCode Counties
----       ----                   ------ ----------- --------
2024-01-01 New Year`s Day          False GB          ENG, NIR, SCT, WLS
2024-01-02 2 January               False GB          SCT
2024-03-18 Saint Patrick`s Day     False GB          NIR
2024-03-29 Good Friday              True GB
2024-04-01 Easter Monday           False GB          ENG, NIR, WLS
2024-05-06 Early May Bank Holiday   True GB
2024-05-27 Spring Bank Holiday      True GB
2024-07-12 Battle of the Boyne     False GB          NIR
2024-08-05 Summer Bank Holiday     False GB          SCT
2024-08-26 Summer Bank Holiday     False GB          ENG, NIR, WLS
2024-12-02 Saint Andrew`s Day      False GB          SCT
2024-12-25 Christmas Day            True GB
2024-12-26 St. Stephen`s Day        True GB

All items where Global=True should be included, for each Region underneath. Some holidays are region specific. EG UK Easter Monday covers England (ENG), Wales (WLS) and Northern-Ireland (NIR). Try adding a filter to check it works first:

Get-PublicHolidays -CountryCode GB -Region ENG | ft

Fetching holidays from URL: https://date.nager.at/api/v3/PublicHolidays/2024/GB
 - dates retrieved: 15
 - dates including global indicator: 15
 - dates including region filtering: 8    <==== IS THIS WHAT YOU EXPECT?

Date       Name                   Global CountryCode Counties     
----       ----                   ------ ----------- --------
2024-01-01 New Year`s Day          False GB          ENG, WLS
2024-03-29 Good Friday              True GB
2024-04-01 Easter Monday           False GB          ENG, NIR, WLS
2024-05-06 Early May Bank Holiday   True GB
2024-05-27 Spring Bank Holiday      True GB
2024-08-26 Summer Bank Holiday     False GB          ENG, NIR, WLS
2024-12-25 Christmas Day            True GB
2024-12-26 St. Stephen`s Day        True GB

So if, we needed to filter Scottish Bank Holidays: it's:

Where are the Holidays for this year gone?

If you have added national holidays, for this year (eg 2024) and you executed the code after y