Everyone is invited to celebrate Tim Hortons' 50th anniversary as the chain will hand free birthday cake donuts out to customers next Saturday (May 17).

Signs posted at restaurants show that certain locations will hand out one donut per customer while supplies last, the Inside Timmies blog reported.

The flavour is not yet available in Canada, but a birthday Timbit with sprinkles was launched in the United States recently, the blog said.

Free donuts are not the only promotion that Tim Hortons is launching as it readies to celebrate its milestone.

Voting is open for the next two days on the "Bring It Back" contest, which asks customers to decide which item the chain should resurrect from previous decades.

Options include the eclair from the 1960s, the sugar twist from the 1970s and the bread bowl from the 2000s. So far the eclair is winning.

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