The concept of 7 days as we know it today can be traced back to ancient civilizations, including the contributions of Hindu Rishi mathematician Aryabhata. The division of the week into seven days has historical, cultural, and astronomical significance.

In Hindu tradition, the seven-day week is called "Saptaha" (सप्ताह), which means "week" in Sanskrit. Each day of the week is associated with a particular planet or deity, which influences the naming of the days in various languages:

1. RabiBar (Sunday): Named after the Sun (Ravi or Surya), which holds immense significance in Hinduism as the source of light and life. Sunday is considered an auspicious day for worship and is dedicated to the Sun God.

2. Sombar (Monday): Named after the Moon (Som or Chandra), which is also highly revered in Hindu mythology and symbolizes emotions, beauty, and calmness. Monday is often associated with the worship of Lord Shiva.

3. Mangalbar (Tuesday): Named after the planet Mars (Mangal), associated with strength, valor, and courage. Tuesday is dedicated to Lord Hanuman, a powerful deity in Hinduism.

4. Budhbar (Wednesday): Named after the planet Mercury (Budh), which represents intelligence, communication, and business. Wednesday is considered a propitious day for activities related to education and learning.

5. Brihaspatibar (Thursday): Named after the planet Jupiter (Brihaspati), symbolizing wisdom, knowledge, and fortune. Thursday is associated with worshiping Lord Vishnu or Guru (teacher).

6. Sukrabar (Friday): Named after the planet Venus (Shukra), associated with love, beauty, and creativity. Friday is considered an auspicious day for weddings and artistic endeavors.

7. SaniBar (Saturday): Named after the planet Saturn (Shani), which symbolizes discipline, justice, and hard work. Saturday is often associated with the worship of Lord Shani or Lord Hanuman.

These associations with planets and deities have influenced various cultural practices and religious traditions throughout history. The seven-day week has become a fundamental timekeeping system globally, with each day carrying its own unique significance and being observed in various ways across different cultures and religions.