TTC riders using their frozen fingers to check vehicle arrival times on their phones via NextBus or other apps encountered some longer — and shorter — waits on Monday than promised.

That’s because the TTC’s New Year’s schedule changes weren’t uploaded by NextBus. The California company, a division of Cubic Transportation Systems, supplies data to the city’s open data site, where it is used by app makers to provide vehicle arrival predictions.

“Even our own boards in subway stations will be wrong,” said TTC spokesman Brad Ross.

An official with Cubic issued an apology, attributing the problem to a “timing error,” expected to be corrected by Tuesday.

In some cases, such as the 512 St. Clair streetcar, the lack of accurate predictions was barely noticeable. On other routes such as the 501, 510 and 509, which had major schedule changes, the failure was more obvious.

“It doesn’t mean all routes are way out of whack . . . but some will be more reliable than others,” said Ross.

Although the issue isn’t on the TTC’s end, the transit agency pays NextBus about $600,000 a year, and the absence of vehicle arrival predictions affects Toronto commuters, he said.

It isn’t the first time such a lag has occurred. It has happened occasionally when schedules change, and it is usually corrected overnight, said Ross.

The TTC changes its schedules more than most transit agencies — about every six weeks.

“NextBus applies an algorithm which combines both the scheduled bus times and GPS co-ordinates of “scheduled” vehicles for each route, which provides us with the prediction,” he said.

About 1.7 million riders use the TTC each day.