count of months between 2 dates

       Gerry Evans     May 9, 2019 5:31 AM  (in response to alvinmac)   

Need number of months between 2 dates  

I'm trying this script for 2 date fields... do the date fields have to be in a specific date format for this to work?  Currently set to dd-mmm-yy

function Scand(cFormat, cString) {

// convert a date or time string to a date object;

var oDate = util.scand(cFormat, cString);

if(oDate == null) app.alert("Error converting " + cString + " with format of " + cFormat, 0, 0);

return oDate;

}

var cDateFormat = "dd/mm/yyyy"; // format for date string;

// Forecast values;

var cForecast = "20/02/2014";

var oForecast = Scand(cDateFormat, cForecast);

// Expiry values;

var cExpiry = "20/03/2015";

var oExpiry = Scand(cDateFormat, cExpiry);

// check that Expiry is not before the Forecast;

if(oExpiry.getTime() < oForecast.getTime()){

app.alert("Expiry before Forecast!", 0, 0);

} else {

// compute the differences;

var nDiffYears = oExpiry.getFullYear() - oForecast.getFullYear(); // diff in years;

// difference in years * 12 months/year + difference in months;

var nDiffMonths = (nDiffYears * 12) + (oExpiry.getMonth() - oForecast.getMonth());

}

// convert year to months and add to months;

event.value = (nDiffYears * 12) + nDiffMonths;