If stored dark, dried and cool you are safe keeping pollen 3 to 4 days. It is difficult to keep viable being highly susceptible to molds.
@CannabianDad recommends;
My storage begins at harvest. When the male flowers are opening and beginning to drop, I take some clean scissors and a clean plate out and clip all the male flowers onto the plate. Once I’m done, I transfer the plate of pollen to a dark and very dry place to dehydrate as much moisture out as I can.
Once the flowers are dry, they are very crumbly - I don’t separate them or crush them too much, I bag 'em with the pollen and a few silica packs, vacuum seal and then I just store them in a cool, dark place.
The package is maybe 3"x3"x.5" all told it doesn’t look like much.
When I want to pollinate I open a bag and use a fine tipped paintbrush on a flower or two, then reseal.
To further explain why I don’t freeze the pollen - organic cells almost always contain water, and when you freeze them the cell walls often rupture. That’s why freezing weed almost always results in some weird tacky texture, and you’re better off storing it in a cool, dark, and dry place - unless you want to make concentrates. Anyone who eats frozen veggies from time to time knows the difference when they bite into something fresh.