Surah At-Tawbah
إِنَّ عِدَّةَ ٱلشُّهُورِ عِندَ ٱللَّهِ ٱثْنَا عَشَرَ شَهْرًا فِى كِتَـٰبِ ٱللَّهِ يَوْمَ خَلَقَ ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضَ مِنْهَآ أَرْبَعَةٌ حُرُمٌ ۚ ذَٰلِكَ ٱلدِّينُ ٱلْقَيِّمُ ۚ فَلَا تَظْلِمُوا۟ فِيهِنَّ أَنفُسَكُمْ ۚ وَقَـٰتِلُوا۟ ٱلْمُشْرِكِينَ كَآفَّةً كَمَا يُقَـٰتِلُونَكُمْ كَآفَّةً ۚ وَٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ مَعَ ٱلْمُتَّقِينَ
Inna ‘iddatasy-syuhūri ‘indallāhiṡnā ‘asyara syahran fī kitābillāhi yauma khalaqas-samāwāti wal-arḍa minhā arba‘atun ḥurum(un), żālikad-dīnul-qayyim(u), falā taẓlimū fīhinna anfusakum wa qātilul-musyrikīna kāffatan kamā yuqātilūnakum kāffah(tan), wa‘lamū annallāha ma‘al-muttaqīn(a).
Indeed, the number of months with Allah is twelve [lunar] months in the register of Allah [from] the day He created the heavens and the earth; of these, four are sacred. That is the correct religion, so do not wrong yourselves during them. And fight against the disbelievers collectively as they fight against you collectively. And know that Allah is with the righteous [who fear Him].
📝 Footnotes
326) Allah SWT has established the orbital period of the Earth around the sun for a year, which is equivalent to twelve months—namely, twelve appearances of the crescent moon resulting from the moon orbiting the Earth. It is the regularity of this time period that serves as the standard for time calculation.