Backbench MSP Rhoda Grant said: "The NHS predicts it will need just over 190,000 donors to secure enough blood for patients in the future and it is particularly important to maintain supplies during the cold weather.
"The Scottish National Blood Transfusion Service celebrated its 70th anniversary this year. Scotland has a record of generosity we should feel proud of.
"I want to encourage every Scot who has not already done so to register to give blood. To help achieve this I believe that employees should have the right to paid time off work to donate blood."