In the Name of Allaah, the Most Gracious, the Ever Merciful…
In his discussion of the various impermissible ways some Muslims show misplaced loyalty and allegiance to the non-Muslims, senior Islamic scholar Shaykh Saalih ibn Fowzaan al-Fowzaan (may Allaah preserve him) states:
#6 – Keeping track of the date using their calendars, especially those that highlight their rituals and holidays, like the Christian (Gregorian) Calendar
It (the Gregorian Calendar) is something that commemorates the birth of the Messiah (may Allaah grant him peace), and something which they invented themselves, not something from the Religion of the Messiah (may Allaah grant him peace). Using this calendar includes sharing with them in the preservation of their rituals and holidays.
To avoid this, the Companions (may Allaah be pleased with them) wanted to establish a calendar for the Muslims in the time of ‘Umar, the (second) Caliph. They ignored the previously established calendars of the disbelievers and began with the Messenger’s emigration (i.e. his hijrah to the city of al-Madeenah).
This proves the obligation to oppose the disbelievers in this and all other things which are specific to them, and Allaah is the One from whom we seek help.
Source: Al-Walaa’ wal-Baraa’ (pp.11-12), Daar al-Imaam Ahmad printing, 1434.
 The English names of some of the months on the Gregorian Calendar have polytheistic origins rooted in Greek, Roman, and other mythology:
- January: named after Janus, their god of doors and gates
- March: named after Mars, their god of war
- May: named after Maia, their goddess of growth of plants
- June: from junius, Latin for their goddess Juno
 The Islaamic Hijri Calendar is not a cultural “Arab” thing, rather it plays a very important role in the life of every Muslim, Arab or not. When it is ignored, Muslims unknowingly can fall into blameworthy neglect related to four of the five pillars of Islaam! This is explained in detail in the lecture: “The Concern of Giving Full Preference to the Kaafir Calendar (16 Ways It Affects Your Practice of Islaam!)” (YouTube/Safeshare)
 When it is not possible to use the Hijri Calendar to coordinate things, like booking a plane ticket for example, then Muslims are allowed to use the non-Muslims’ calendars when needed. However, these instances of necessity do not become a proof that we can completely abandon our Islaamic calendar and fully adopt the non-Muslims’ one.
 Muslims should embrace their calendar, since it was founded by the rightly-guided Caliph, ‘Umar ibn al-Khattaab (may Allaah be pleased with him), and none of the Companions had any problem with it. The Prophet (may Allaah raise his rank and grant him peace) said:
عليكم بسنتي وسنة الخلفاء الراشدين المهديين عضوا عليها بالنواجذ
“Upon you is (to follow) my Sunnah, and the Sunnah of the rightly-guided Caliphs, bite onto it with your molars.” (Aboo Daawood and others, authentic)
Thus, as mentioned by Shaykh Saalih al-Fowzaan, the use of the Hijri Calendar instead of other calendars should be understood an issue of walaa’ and baraa’ (loyalty to Islaam).
 The best way to implement this good reminder (in case you are not following the Hijri Calendar already) is to learn today’s date on the Hijri Calendar, and then begin referring to the date in Hijri in some of the ways you communicate with other Muslims. For example, you could date your emails (at least) by adding the Hijri date at the end. It is hard to forget the months of a calendar you actually live by!
Use this helpful one-page PDF to learn and memorize the Islaamic months if you do not know them already.
And Allaah knows best.
Translation and Commentary: Moosaa Richardson (1434-08-19)