And more than twice as many were nabbed on a weekday than on the weekend.
The new police intelligence comes as police warn they are out anywhere and any time detecting those driving under the influence of illicit substances.
Every highway patrol car can test for drugs, alongside Victoria Police’s drug bus fleet.
Victoria Police figures show around 5200 of the 8400 drug drivers detected in the last financial year were caught between 6am and 6pm.
It compares with almost 3200 detected between 6pm and 6am.
Friday had the most detections of any day, with 1400, ahead of Saturday, Sunday and Thursday, according to police.
Victoria Police has been scheduling special daytime and early-morning operations to keep drug drivers on their toes and remind all drivers police are out testing for drugs around the clock.
The force conducts around 150,000 roadside drug tests a year.
Anyone caught drug driving faces heavy fines and a loss of licence.
First-time drug drivers alone will be fined $593 and have their licence suspended for six months.
They must also complete a drug-driver program within three months or their licence or learner permit will be cancelled.
Repeat drug drivers face fines of up to $23,710 and will have their licence cancelled for at least 12 months.
Police also have the power to impound a vehicle for drug-driving offences.
As well as enforcement, police can also connect drug users with support services to keep them and other road users safe.
The detection data is based on positive secondary drug tests that have been confirmed through laboratory analysis.
State Highway Patrol Acting Inspector Kevin Vincent said police were out anywhere and at any time to drug-test drivers.
“People might think illicit drug use is confined to the weekend, but the reality is our members are seeing people getting behind the wheel on illicit substances right across the week,” he said.
“That’s why we have highway patrol vehicles and our drug bus fleet out day and night to keep all road users safe.
“There really is nowhere to hide.
“Drugs cause more deaths on our roads than alcohol — it’s just not worth the risk.”