* S&P has risen in 12 of past 14 sessions
* Workday revenue forecast below expectations
* Futures up: Dow 17 pts, S&P 1.75 pt, Nasdaq 7.25 pts
By Ryan Vlastelica
NEW YORK, Nov 25 (Reuters) - U.S. stock index futures were slightly higher on Tuesday as the market's long-running upward bias looked to continue, though further gains may be difficult to come by in a week that's expected to be quiet.
* Equities have been strong of late. The S&P 500 is up for 12 of the past 14 sessions, and all three major indexes are coming off five-week streaks of gains. Both the Dow and S&P closed at records on Monday, and the S&P is up more than 13 percent from a intraday low hit in mid-October.
* Much of the rally has come on bets for more stimulus from central banks around the world, which is expected to continue supporting markets, though the swiftness of the gains since October could spur some profit taking.
* Market moves this week could be amplified by low volume, which is expected with some market participants out for the Thanksgiving holiday. The U.S. stock market will be closed on Thursday and will close early on Friday.
* In company news, Workday Inc late Monday forecast fiscal 2016 revenue below expectations. Nuance Communications Inc, whose voice recognition software runs Siri on Apple Inc's iPhones, late Monday reported revenue growth of 6.4 percent.
* Yingli Green Energy Holding Co Ltd reported a quarterly loss that narrowed from the prior year, while revenue fell 7.5 percent. Shares fell 1.3 percent to $2.95 in premarket trading.
* Restaurant shares may be in focus after U.S. government introduced sweeping new rules that require chain restaurants and large vending machine operators to disclose calorie counts on menus to make people more aware of the risks of obesity posed by fatty, sugary foods.
Futures snapshot at 6:47:
* S&P 500 e-minis were up 1.75 point, or 0.08 percent, with 81,307 contracts changing hands.
* Nasdaq 100 e-minis were up 7.25 points, or 0.17 percent, in volume of 12,645 contracts.
* Dow e-minis were up 17 points, or 0.1 percent, with 13,604 contracts changing hands.
Editing by W Simon