Well, everyone knows their own climate "pocket" best, but where I am (quite a bit south of you), nighttime temps are still in the 30's, & I had frost this morning. Won't be planting out my warm-weather tenders (tomatoes, peppers, eggplant, okra) until Mother's Day weekend. Thus I won't be hardening off for another couple of weeks yet.
Another thing - how did you "harden them off"? You can't just take them from inside & stick them out in the sun. That will kill them. "Hardening off" means you first put them out in a shady place for a couple of hours to half a day & then bring them back inside. You do this for a couple of days. Then you start leaving them where they can get just some partial direct sun - still bringing them in at night. Finally, you start leaving them in full direct sun, bringing them in only if nighttime temps are going to drop below the mid-forties. Depending on the weather & the size & sturdiness of the seedlings, this procedure can take anywhere from a week to 2 weeks. That's acclimation.