Auto generate the date and time but display as yyyymdHHMM

[AAO5]

I'm looking to create a field that is auto generated each time i use the pdf. This field needs to auto generate using date and time but be displayed as "yyyymdHHMM". any assistance would be greatly appreciated. 

[Nesa Nurani]

As document level script use this:

var date = new Date();
this.getField("Date").value = util.printd("yyyymdHHMM",date);

adjust field name if neccessary.