Frost dates and flowers

So yesterday I splurged and bought a bunch of flower seeds which I thought would be good for bees. Some of them, like borage I know are good for bees. Thing is I was in a hurry and didn't read the packet info. Several of them say to sow sever weeks BEFORE the last frost date. Which was more than a month ago this year. Now I know its not a day length thing since some places still are getting frosts, so it must be a temp thing right? I'm wondering if I can so them any way or maybe fake them out by dropping them into my moms freezer for a day or two? I don't know stabbing in the dark here I've never really done flowers. There are a couple herby type things too. A few examples

Borage
***(package torn on first several letters) -obelia
Blue Boy Bachelor buttons
Chervil
Catnip

Just want to make sure I'm not throwing away good seed on a hopeless endeavor

Borage and batchelor buttons self sow, they just want you to give it enough time to flower before frost. You can probably start them outside, though they may bloom later this year than in the future. The bees love borage.
Chervil is a cool weather loving green. Won't taste too nice if it gets hot, really a spring/fall specialty. If you still have a month, you might get some to try, could let it flower and raise up more in the fall.
Things like zinnias or marigolds that say start indoors just take a long time to come to flower but won't survive a frost, so you raise them up as starts, like tomatoes. That can take several weeks, which is what the date on the package is mostly about.
Fun!