Despite adding weekend delivery and hiring extra seasonal staff, Canada Post warns time is running out to ensure packages arrive in time for the holidays.

The postal service recommends that Canadians choosing standard shipping should get items out by end of Wednesday (Dec. 11) to give them the best chance at arriving on time for Christmas.

Canada Post has experienced a 30 per cent jump in package deliveries compared to 2017, said Alain Robitaille, president of the Montreal chapter of the Canadian Union of Postal Workers (CUPW).

He said the fact Black Friday occurred so close to peak holiday season this year meant it "all came together" at the same time.

Part of the problem is Canada Post takes on packages that private carriers like Purolator or UPS say they can't deliver, he said.

"If you order from Amazon, they will choose the delivery method for the package. If certain competitors don't have enough space to do the work, it goes to Canada Post," he said.

He said two packages out of three end up being delivered by Canada Post.

In Montreal, Canada Post has hired an extra 70 people to help with deliveries. It has also opened an overflow centre, and is looking at opening a second.

Nancy Beauchamp, CUPW director for the greater Montreal region, said workers who are processing and delivering the packages are already doing overtime.

"If there are delays, it's not because people don't want to make deliveries. It's a question of volume and capacity," she explained.

Beauchamp warned just one weather event could push deliveries back further.

Canada Post estimates it will deliver about 1.4 million packages a day nationwide between mid-November and mid-January, a total of about 80 million packages.

Robitaille said despite Canada Post's warning that packages should be ordered by Dec. 11, he's optimistic that even if orders come in later, they'll arrive before the holidays.

"Last year, we had a backlog of many weeks," he said. "And we were able to take control of the backlog in two or three days."