It is compulsory as Muslims to learn the Islamic days of weeks as it would be useful for us in some situations.
In case, you find yourself in an Arabic country you have to be familiar with how they count days so as to be able to flow with them.
The Islamic days of the week are written below:
Monday الاثنين (al-ithnayn)
Tuesday الثلاثاء (ath-thulathaa)
Wednesday الأربعاء (al-arbi’aa)
Thursday الخميس (al-khamees)
Friday الجمعة (al-Jumu’ah)
Saturday السبت (as-Sabt)
Sunday الأحد (al-ahad)