Untitled

dabblet.html

Drag this link into your 
bookmark bar:
<a href='javascript: function () {  var field = document.querySelector("#promotion_days");  function days(date) {    var parts  = date.split("-"); // YY-MM-DD    var year   = parseInt(parts[0]) + 2000;    var month  = parseInt(parts[1]) - 1;    var day    = parseInt(parts[2]);    console.log(year, month, day);    var now    = new Date();    var then  = new Date(year, month, day, 0,0,0,0);    var days = Math.ceil((then - now) / 1000 / 3600 / 24);    return days;  }  var date = prompt("When should this gift expire? Tell me in YY-MM-DD format!");  field.value = days(date);}'>Gift Expiry</a>

<br>
<br>

Then while looking at a gift form, click the bookmarklet :)

settings.json

{"view":"split","fontsize":"100","seethrough":"","prefixfree":"1","page":"html"}