If you’re an iPhone owner you can get Hijri dates as a additional calendar to appear on your device.
Here’s how to do it:
Step 1: Tap on the Settings icon
Step 2: Tap on Calender
Step 3: Tap on Alternative Calendars
Step 4: Choose Islamic
Thats it! The Hijri calendar will now appear on your lock screen below the Gregorian Calendar, and also appear on the Calendar app!