There are summer annuals, Cool season annuals and then perennials.
Rule is simple.
Summer annuals in March-Apr and then maybe in Late August.
Cool Season in October-November.
Perennials can be sown in March-April window as well as Oct-November.
This should not be a problem to differentiate which are summer annuals and which are cool season or what is perennials.
These are summer annuals......Rest everything is cool season
Summer Annuals
Cool Season Annuals
Lastly Flowers/ornamental plants are very delicate plants generally not as hardy as vegetables. They require precise temperatures for germination. We should be discussing temperatures not Months.