Subscription expiration date field uses user timezone but interval is calculated from "now" in the server timezone.

As per the title, the subscription expiration date field uses the user timezone, but the interval is calculated from "now" in GMT. This is not such a problem with annual subscriptions, but certainly is for 24 hour subscriptions.

        { "RULE" : {
            "IF" : [
              { "data_is_empty" : { "data" : [ "account:field-commerce-sp-validity" ] } }
            ],
            "DO" : [
              { "data_set" : { "data" : [ "account:field-commerce-sp-validity" ], "value" : "now" } }
            ],
            "LABEL" : "User has no subscription yet"
          }
        },

Is it possible to replace "now" with "now + user timezone offset"? Alternatively the expiration date field could be changed to use UTC, but this is less than ideal if you display the expiration date to the user.