What are your personal exemptions?
After each absence of 24 hours or more
You can claim up to CAN$50 worth of goods without paying any duties. This is your personal exemption. You must have the goods with you when you arrive and you cannot include tobacco products or alcohol beverages in this exemption.
If the goods you bring in are worth more than CAN$50 in total, you cannot claim this exemption. Instead, you have to pay full duties on all goods you bring in.
After each absence of 48 hours or more
You can claim up to CAN$200 worth of goods without paying any duties. You must have the goods with you when you arrive. Although you can include some alcoholic beverages and tobacco products, only a partial exemption will apply to cigarettes, tobacco sticks, or loose tobacco. You may have to pay a minimum duty on these products. You can find more details on the next page under "Tobacco and alcohol."
After each absence of seven days or more
You can claim up to CAN$750 worth of goods without paying any duties. With the exception of alcoholic beverages and tobacco products, you do not need to have the goods with you when you arrive. Although you can include some alcoholic beverages and tobacco products, only a partial exemption will apply to cigarettes, tobacco sticks, and loose tobacco. You may have to pay a minimum duty on these products.
To calculate the number of days you have been absent, do not include the date you leave Canada but include the date you return. It is dates that matter, not times. For example, we consider you to have been absent seven days if you left Friday the 7th and returned Friday the 14th.
Who is eligible for these exemptions?
You are eligible for a personal exemption if you are a:
Canadian resident returning from a trip abroad;
former resident of Canada returning to live in this country; or
temporary resident of Canada returning from a trip abroad.
Even young children and infants are entitled to a personal exemption. As a parent or guardian, you can make a customs declaration for a child, as long as the goods you are declaring are for the child's use.
for more info, check the link:
http://www.ccra-adrc.gc.ca/E/pub/cp/rc4044/rc4044-e.html