HONOLULU -- The international convention for Jehovah's Witnesses officially began Thursday, and it is a much-needed shot in the arm for Hawaii's economy during a traditionally slow time of the year.

Nearly 30,000 Jehovah's Witnesses from 34 countries from around the world will participate in the convention over two weeks.

"Normally we are slow at this time of year, and it's a great piece of business for us. It's fabulous. You look around this room; we've 13,000 or 14,000 friends from all over the world," Hawaii Convention Center General Manager Joe Davis said.

There are so many delegates the convention had to be broken into two parts.

The delegates are spending money while they are in the islands. The hotels in Waikiki are packed and stores and restaurants report seeing a boost, too.

"Absolutely, it's a wonderful boost for not only our business, but everyone around here," said Bryan Packer, of Cheesecake Factory.

"You are going to see them all over Waikiki. They are all going to be wearing their lapel badges, which you can see that say 'Keep on the Watch.' They'll be in all the hotels and restaurants for the next couple of weeks at least," said David Fitzgerald, of Jehovah's Witness.

The neighbor islands may see some residual business as well.

"We have friends who were here before the convention. So, they traveled to the other islands and I'm sure they will be traveling after the program here," Tony Cooper said.

There are some estimates the large religious gathering will pump about a $100 million into the economy.

The Jehovah's Witnesses convention runs through Nov. 29.