Day… Lord Krishna married the plant Tulsi.
Most auspicious day of Hindu calendar when marriage is possible without mahurat.
Radha disapproving her Lord Krishna’s attachment to Tulsi and cursed her to become a plant. Angry Krishna declared he’ll not accept any food/ beverage without Tulsi leaves. He promised he’ll visit earth once a year and marry her; & hence Tulsi Vivah is celebrated on this earth.