Not able to update standard cost

We had someone post an inventory transaction dated 12/31/2015 instead of 12/31/2014. (She posted before I was able to place the period “On Hold” since we’ve made this mistake before).

Now I can’t update the standard on about 80 items because of the financial date.

Is there another way around this? I can’t leave the cost as is, our COS will not be correct and it’ll set us up for inventory count variances at year end. Those 80 items roll up into several BOM’s.