After a cold spell at the Broadway box office, sales heated up last week thanks to the date-night business around Valentine’s Day and the long-weekend traffic of President’s Day — all while Sara Bareilles proved her box office might, spurring a sales stampede at “Waitress” in the wake of the announcement of her casting in the show.

According to the musical’s producers, “Waitress” ($861,111) racked up $2 million after they announced that Bareilles, the singer-songwriter who wrote the score, would take on the title role for ten weeks later this year — which suggests that weekly sales figures will soar once Bareilles’ run starts, and her fans start packing the theater.

Meanwhile, the production’s weekly gross rose 28% as overall business jumped, thanks to the one-two punch of Valentine’s and President’s Day. Musicals in particular did well, with 11 shows topping $1 million apiece and “Hamilton” ($2,866,806) well above $2 mil. The rave reviews for Glenn Close in “Sunset Boulevard” ($1,300,709 for seven) kicked that show up to a new high, while Jake Gyllenhaal in “Sunday in the Park with George” ($855,538 for seven previews) reported pretty robust numbers for a show in one of the street’s smaller houses.

But perhaps the real head turner was “Come From Away” ($322,942 for three previews). Don’t know much about that one? You’re probably not alone — the musical, the heartfelt story of a small town accommodating a deluge of rerouted air travelers in the wake of 9/11 — has come in largely under-the-radar. The show’s supporters, though, have put bets on the production become a sleeper hit this season. That first weekly tally, ringing in more than $100,000 per performance, suggests there may already be some grassroots buzz growing in the wake of the musical’s well-received out-of-town runs. The coming weeks will show whether “Come From Away” can maintain that kind of momentum.

Also joining the Broadway fray last week were two plays, both starting fairly modestly: “The Price” ($280,192 for four), the Roundabout Theater Company’s Arthur Miller revival starring Mark Ruffalo, and “Significant Other” ($226,779 for seven), the Broadway transfer of a well-reviewed Roundabout premiere.

Overall Broadway sales last week soared by $5.8 million (or about 30%) to $25.6 million for 26 shows now playing. Attendance, too, jumped thanks to holiday traffic, adding some 25,000 theatergoers to total 219,844. To judge from recent years, though, the boom will likely subside next week, with momentum really rising in March as the season kicks into high gear.