Time format interpreter

snippet.js

(function(){
  var tsplit = /[^\d]/, pad_time = function (time) {
    if (time<10 && time.length<2) {
      return '0' + time.toString();
    }
    else {
      return time;
    }
  },
  normalize_time = function (inp) {
    var ts = jQuery(inp).val(), ta = ts.split(tsplit), h=0, m=0;
    if (ta.length == 1) {
      switch (ts.length) {
        case 1:
          h = ts;
          break;
        case 2:
          if (ts<24) {
            h = ts;
          }
          else {
            h = ts.substr(0, 1);
            m = ts.substr(1, 1);
            if (m<6) {
              m *= 10;
            }
          }
          break;
        case 3:
          h = ts.substr(0, 1);
          m = ts.substr(1, 2);
          break;
        case 4:
          h = ts.substr(0, 2);
          m = ts.substr(2, 2);
          break;
      }
    }
    else {
      h = ta[0];
      m = ta[1];
      if (m<6) {
        m *= 10;
      }
    }
    if (m>59) {
      h = parseInt(h, 10) + (m - m%60) / 60;
      m = m%60;
    }
    jQuery(inp).val(pad_time(h) + ':' + pad_time(m));
    if (jQuery(inp).val().length < 5 && m==0) {
      jQuery(inp).val(jQuery(inp).val() + '0');
    }
  };

  jQuery('#starts_time, #ends_time').change(function() {
    normalize_time(this);
  });
})();