NEW YORK — Makers of sleepwear and loungewear say their appointment books are filled this week.

January typically is regarded as one of the smallest markets overall for innerwear, but it’s an important time for the robe and sleepwear firms, who will be discussing promotional programs with retailers, as well as marketing strategies and co-op advertising, looking ahead as far as fall.

Retailers also are expected to complete spring orders. Vendors note that a good number of smaller specialty stores and even some big stores waited until they got Christmas business results before committing open-to-buy dollars for spring. Additionally, some sleepwear and robe vendors will take the opportunity to preview transitional goods and ideas for fall selling.

Summing up retailers’ thoughts, Leslie Freytag, vice president and divisional merchandise manager of intimate apparel at Neiman Marcus, Dallas, said: “I’ll be in New York this week to wrap up spring and finish up with Mother’s Day items. I’ll also be taking an early first look at fall ideas.”

J. Thomson Wyatt, president of Vanity Fair Mills, a VF Corp. division, said, “We are expecting a good attitude from retailers because newness is still driving their innerwear business. We were pleasantly surprised by the good sell-throughs at stores during Christmas.”

Niko Oreopolis, an owner of Nap Inc., a maker of daywear, sleepwear and loungewear under the Nap label and private label, said work on special programs with mass merchandisers and department stores will be the highlight of the week. He noted that the number of units ordered in the programs average between 20,000 and 100,000.

“We are projecting overall sales gains of between 40 and 50 percent for 1994,” he said, noting that texture, fabric mixes and fashion colors and prints will be key factors.