If you're thinking of quitting smoking, it's probably a Monday.

U.S. researchers monitored Google search queries over the past five years in English, French, Chinese, Portuguese, Russian, and Spanish. Search volumes peaked on Monday, almost every week.

Researchers from San Diego State University, the Santa Fe Institute, The Monday Campaigns, and the Johns Hopkins Bloomberg School of Public Health their findings Monday in the Journal of the American Medical Association.

The research team found that during the study period, the number of queries in English on Mondays was 1 per cent larger than on Tuesdays, 11 per cent larger than Wednesdays, 22 per cent larger than Thursdays, 67 per cent larger than Fridays, 145 per cent larger than Saturdays and 59 per cent larger than Sundays. In total for all six languages, Monday query volumes were 25 per cent higher than the combined mean number of searches for Tuesday through Sunday.

"Popular belief has been that the decision to quit smoking is unpredictable or even chaotic," said lead author John W. Ayers of San Diego State University. "By taking a bird's-eye view of Google searches, however, we find anything but chaos. Instead, Google search data reveal interest in quitting is part of a larger collective pattern of behavior dependent on the day of the week."

"If you're a smoker, just remember: quit this Monday," he added. "Everyone else is doing it."