Time between 2 donations
For whole blood donations, the law allows donations to be made in observance of a wait of at least 2 months between 2 donations. Nonetheless, the Red Cross recommends 3 months. Either way, you are allowed to donate blood no more than 4 times over 365 days.
Plasma donations may be made every 15 days and you are allowed to donate a maximum of 15 litres of plasma per year.
For platelets, you need to wait 1 month between 2 donations. A 2-week wait is an exception. The maximum number of platelet donations (including blood donations) is 24 per year (365 days).