BANGKOK: Following the death of King Bhumibol Adulyadej last week, Thailand has entered a period of national mourning which will have wide-ranging effects on the country's media owners and advertisers.

The government has issued media guidelines requiring the cessation of all entertainment for a month and the closure of YouTube for a week, while all newspaper content and advertising must appear in grey and digital billboards are being shut down for a period.

Agencies will stop all commercial advertising for seven days and all on-ground activities and entertainment for 30 days, with clients being invited to change existing spots into condolence ads.

"The whole country will come to a standstill for seven days," Tharaputh Charuvatana, UM Thailand CEO, told Campaign Asia-Pacific.

"All media outlets including the online media will be following the rule to not broadcast content with entertainment elements."

There remains a degree of uncertainty about how long the measures will remain in place. Facebook, for example, has temporarily stopped delivering ads to users in Thailand and said in a blogpost "We don't yet know the duration of the mourning period", but thought it could be as little as seven days.

The official mourning period, however, is one year, and Tharaputh expected that it might be three months before the mood of the country lifted, reflecting the veneration in which the long-reigning monarch was held.

"The overall tone of our ad content for the coming months will be more serious to suit the national tragedy facing our nation," he said. "It will be inappropriate to showcase our content in a light-hearted manner as we used to."

While industry figures have been understandably reluctant at this time to comment on the possible effects on their business, it seems clear that an extended period of mourning will have a potentially significant impact on both consumer and marketer spending.

Warc's data show that the Thai ad market was worth approximately US$3.8bn in 2015.

Data sourced from Campaign Asia-Pacific; additional content by Warc staff