In most Western countries, Sunday is part of the weekend and most Christians see it as a day of worship and rest. Practising Christians worship in many different ways and have different traditions but most will go to church, sign hymns, listen to Bible readings, say prayers and spend time together.
Worshippers from other faiths and cultures also celebrate holy days, but at different time of the week. Friday is a day for Muslims to gather in the mosque for prayers and Saturday (Shabbat) is a day of rest for Jewish people.
Useful Documents –
World-festivals-and-celebrations-calendar