With the Gotham return of tuner “Dr. Seuss’ How the Grinch Stole Christmas” confirmed for a 17-day run this December, the Christmas season is shaping up to become an intriguing test as legiters become increasingly interested in programming seasonal fare.“Grinch,” a San Diego perennial that earned its Broadway stripes with limited Rialto runs in 2006 and 2007, has locked in plans to play the Theater at Madison Square Garden Dec. 13-30. Show joins a slate of yuletide stage offerings that this year includes the musical adaptation of “A Christmas Story,” lined up for Broadway’s Lunt-Fontanne Theater, and the annual Rockettes’ “Radio City Christmas Spectacular.” A return engagement for “Elf,” which played the Rialto in 2010, is largely expected to land at another Main Stem venue, probably the Al Hirschfeld Theater. That run, however, remains unconfirmed by producers and the show’s reps. If “Elf” does materialize, it’ll mark the first time that two Christmas outings will play Main Stem venues during the same holiday frame. And with “Christmas Story,” the Rockettes and “Grinch” all in the picture, New York’s mistletoe season could encompass four separate holiday-themed stage offerings for the first time in recent memory. Broadway producers began experimenting with limited-run holiday outings with “Grinch” in 2006. It all looks poised to offer insight into just how many such productions can be sustained by the city’s annual influx of seasonal tourist auds. For producers, a brief seasonal run of a new musical is already a tricky business. As indicated by Broadway’s track record — “Grinch” in 2006 and 2007, “Irving Berlin’s White Christmas” in 2008 and 2009 and “Elf” in 2010 — holiday outings mostly attain big-hit numbers only between Turkey Day and Christmas. (Grosses from shows at Radio City and Madison Square Garden are not reported by presenter MSG Entertainment.) Producers have aimed to maximize profits from short runs in a number of different ways. For one thing, most such Rialto productions are modeled to yield profits only after multiple stagings in New York and beyond. “White Christmas,” for instance, landed on the Rialto after earlier annual stints in markets around the country. “Christmas Story” toured last year, and “Elf” was always conceived with the idea that the show would return in a future incarnation on Broadway or elsewhere. Performance schedules are tweaked to boost revenue, with many shows playing nine perfs per week (vs. the usual eight) in December. “Grinch” played as many 15 perfs in a single week. The long-standing Rockettes engagement has always offered competish to Broadway’s holiday outings, and Madison Square Garden also has often programmed holiday fare such as “A Christmas Carol.” More recent years, however, have seen MSG showcase titles that are less explicitly holiday-centric, including Cirque du Soleil’s “Wintuk” and, last year, “Peter Pan.” Over the past few years, biz over the holiday frames — always the most profitable of the year, thanks to an annual spike in razzledazzle-hungry tourists — has seemed to hold up for Christmas shows despite the increasing number of titles looking to capitalize on yuletide themes. (“Elf,” for instance, pulled in more than $1 million per week for six weeks, at one point approaching $1.6 million.) This year looks primed to test how many shows the market can take before it’s oversaturated.