IT was nearly 6 p.m. on Friday, an hour when many New Yorkers need a drink, and Sera Chi, the owner of the Dashing Diva nail salon on the Upper West Side, was greeting her regulars. “It’ll be about 45 minutes for a manicure,” she told them, “but you can have a Cosmo now.”

Soon about 20 women were sipping pink drinks while choosing polish colors and waiting to be led to the manicure and pedicure stations. There, about 15 more women were having their nails clipped, filed and painted, their martini glasses balanced on any available surface: on top of nail-drying ovens, on the armrests of pedicure chairs.

Cocktail night at the nail salon has become a popular tradition around the city, a time when shop owners can serve drinks (sometimes legally), knowing that their patrons are unlikely to be driving home. Keep reading.