SAN FRANCISCO — Apple sent out its media invitations for a March 9 event in San Francisco — widely expected to be the official debut of the company’s first wearable device, the Apple Watch.

The company’s invites always come with a cryptic one-liner, which in this case was “Spring Forward.” The phrase is practically a giveaway that the watch will be the star of the show, which takes place the day after the start of daylight saving time, when people perform the annual ritual of setting all their timepieces an hour ahead (if their devices don’t do so automatically, that is).

Apple first announced that it was developing a watch last fall, after months of speculation that the tech giant was going to wade into the market. The watches that Apple had on display in October were prototypes, with features such as the ability to receive calls, send and receive messages and track fitness stats when the watch is paired with a phone.

The Apple Watch is expected to start at $349 and come in three main varieties — a sports watch, a middle-tier watch and a luxury gold watch. The company hasn’t made any announcement about how expensive that top watch will be, although analysts expect it will be in the thousands.

Apple chief executive Tim Cook said in the company’s latest earnings call that the watch will begin shipping in April.

It may seem that Apple is a latecomer to the wearables market; Samsung, after all, has released multiple generations of its smartwatches. But the market is fairly wide open. Canalys reported last month that just 720,000 wearable devices running Android Wear — Google’s wearable technology operating system — shipped in 2013.

“All eyes are now on Apple,” the analysis firm said in a release. “The product will dramatically grow the market for smart bands and wearables overall.”

First Published February 26, 2015, 6:41 p.m.