In an interview, Smart Spokesman Ramon R. Isberto said a promotion that allows subscribers to make unlimited calls at night and send as many text messages as they can would not be made available from Dec. 23 to Dec. 25, and from Dec. 30 to Jan. 1.

Likewise, a similar promotion from Globe will not be made available on Dec. 24 and 25, and on Dec. 31 and Jan. 1, said Froilan M. Castelo, Globe’s regulatory division head.

This is to help prevent their networks from overloading at a time when most Filipinos greet their friends and relatives with Christmas greetings.

“What we are doing is managing our network, in case there are any serious obstructions [during the holidays],” Mr. Isberto said.

“We are not taking any chances. We want to protect the network from abuse,” Mr. Castelo said. “We want to avoid any congestion. We just want to clear the airwaves,” he added.

A billion text messages are sent locally everyday as estimated by both Smart and Globe. This can increase during the holidays as Filipinos greet their friends and relatives.