Happy Promise Day 2021 WhatsApp messages: The fifth day (Promise Day) of Valentine’s Week is here. The most meaningful and significant day of Valentine’s Week is Promise Day which falls on the fifth day of the week. On this day, lovers promise each other to be together in thick and thin of life. With the ongoing 7-day celebration of Valentine’s week, Promise Day is celebrated on February 11 every year. It is the 5th day of Valentine’s week after Rose Day (February 7), Chocolate Day (February 8) and Propose Day (February 9) and Teddy Day (February 10), and is celebrated by people across all age groups and especially young couples.