If the sap is 34-35 degrees it will be fine for at least a week. The trick is keeping it cold. I have actually had it get 10 days old at the beginning of the season and other than being a little darker grade, it was very good syrup.
Nothing happening up here yet other than getting things ready, some guys have started drilling, but there has been virtually no sap yet. My test tree had about a 1/4 cup from 2 days.