Date: predate test; suggestion

[arfa2]

I am not sure if this is useful? I wondered about you having a space for add-ons, or snippets - which is really what this is. I imagine different users create bits of code - that work for them - and could be useful for others. You could list - but not support or guarantee.
Anyhow...
This uses date format yyyy-mm-dd or,
yyyy-mm-dd hh:mm

messages = {
... as per,
mustPostDate : 'Depart <i>after</i> Arrival'
},

  Validator = {

    // postDate check; end date must be after start date
    postDate : function( tmp, self ) { 
            var startDate = self.form.querySelector('input[name="'+ tmp.arg +'"]').value;
        if (startDate.length>'0') { // startDate must be set
            // work on start date
        if (/ /g.test(startDate)) { // with time: "yyy-mm-dd HH:MM" - 24hr clock
            var startRaw = startDate.split(' ')[0].split('-');
            var timeRaw = startDate.split(' ')[1].split(':');
                var hours = timeRaw[0];
                var mins = timeRaw[1]; }
        else { var startRaw = startDate.split('-'); // plain date: "yyy-mm-dd"
            var hours = '0'; var mins = '0'; }
        // Date.UTC(yy,mm,dd,hh,mm,ss); = milliseconds
    var startStamp = Date.UTC(startRaw[0],startRaw[1]-1,startRaw[2],hours,mins,0)/1000;
            // work on end date
        if (/ /g.test(tmp.val)) { // with time: "yyy-mm-dd HH:MM" - 24hr clock
            var endRaw = tmp.val.split(' ')[0].split('-');
            var timeRaw = tmp.val.split(' ')[1].split(':');
                var hours = timeRaw[0];
                var mins = timeRaw[1]; }
        else { var endRaw = tmp.val.split('-'); // plain date: "yyy-mm-dd"
            var hours = '0'; var mins = '0'; }
    var endStamp = Date.UTC(endRaw[0],endRaw[1]-1,endRaw[2],hours,mins,0)/1000;
            return endStamp >= startStamp || messages.mustPostDate; }
       else return; // startDate not yet set
    },
// etc...
  }; // END Validator =

I think that's it.

[hsnaydd]

This can be added as an example in the next version. It can be followed #44.