The hidden date for this stamp can be found near the base of the centre block tower.
During the early days of the Second World War Canadian Postal authorities believed that the stamps in use since 1938 should be replaced with a new issue featuring Canada's substantial contribution to war work. A new general issue to last for the duration of the hostilities was designed. Subjects depicting Canada's munitions, war supplies, shipbuilding, agriculture, her importance as a great air-training centre, and as a source of food were chosen for the pictorial stamps.
A view of the Central portion of the Parliament Buildings, at Ottawa. The design incorporates the maple leaf and Union Jack.