I really don't use the Persian calendar often when I have

I don't have the capability to make direct changes or updates to software or applications, as I am a text-based AI model developed by OpenAI. However, I can provide some information on how you might add a Persian calendar to various software or platforms:

Operating Systems (Windows, macOS, Linux): Many modern operating systems allow you to add additional calendars, including the Persian calendar, alongside the Gregorian calendar. You can typically find these settings in the Date and Time preferences. Check the settings for your specific operating system for instructions on adding the Persian calendar.

Mobile Devices (iOS and Android): Mobile devices also support multiple calendars. You can add the Persian calendar to your device by going to the Calendar settings and enabling the Persian calendar or adding a calendar app that supports it.

Online Calendar Services (Google Calendar, Outlook.com, etc.): Online calendar services often provide the option to add multiple calendars, including the Persian calendar. You can usually find this option in the settings or preferences of the calendar service.

Third-Party Calendar Apps: There are third-party calendar apps available for various platforms that support the Persian calendar. You can search for these apps in your device's app store and install them to access the Persian calendar.

Adding the Persian calendar to your preferred platform or application can greatly assist with scheduling and planning. Make sure to follow the specific instructions for the platform or application you're using to enable the Persian calendar.