JS (JavaScript) custom dateadd and datediff functions and method of obtaining the current date

Processing date in JS is relatively junk. The following functions may help you better process the date in Js.
Including dateadd, datediff, and current date

Current date
VaR d = new date ();
VaR theday = D. getyear () + "-" + (D. getmonth (). tostring (). length> 1 )? (D. getmonth () + 1): "0" + (D. getmonth () + 1) + "-" + (D. getdate (). tostring (). length> 1 )? D. getdate (): "0" + D. getdate ());

Dateadd Function
Function dateadd (interval, num, datevalue)
{
VaR newcom = new timecom (datevalue );
Switch (string (interval). tolowercase ())
{
Case "Y": Case "year": newcom. Year + = num; break;
Case "M": Case "month": newcom. Month + = num; break;
Case "D": Case "day": newcom. day + = num; break;
Case "H": Case "Hour": newcom. Hour + = num; break;
Case "min": Case "Minute": newcom. Minute + = num; break;
Case "S": Case "second": newcom. Second + = num; break;
Case "Ms": Case "msecond": newcom. msecond + = num; break;
Case "W": Case "Week": newcom. day + = num * 7; break;
Default: Return ("invalid ");
}
VaR now = newcom. year + "/" + newcom. month + "/" + newcom. day + "" + newcom. hour + ":" + newcom. minute + ":" + newcom. second;
Return (new date (now ));
}

Timecom object
Function timecom (datevalue)
{
VaR newcom;
If (datevalue = "")
{
Newcom = new date ();
} Else {
Newcom = new date (datevalue );
}
This. Year = newcom. getyear ();
This. month = newcom. getmonth () + 1;
This. Day = newcom. getdate ();
This. Hour = newcom. gethours ();
This. Minute = newcom. getminutes ();
This. Second = newcom. getseconds ();
This. msecond = newcom. getmilliseconds ();
This. Week = newcom. getday ();
}

Datediff Function

Function datediff (interval, date1, date2)
{
VaR timecom1 = new timecom (date1 );
VaR timecom2 = new timecom (date2 );
VaR result;
Switch (string (interval). tolowercase ())
{
Case "Y ":
Case "year ":
Result = timecom1.year-timecom2.year;
Break;
Case "M ":
Case "month ":
Result = (timecom1.year-timecom2.year) * 12 + (timecom1.month-timecom2.month );
Break;
Case "D ":
Case "day ":
Result = math. round (date. UTC (timecom1.year, timecom1.month-1, timecom1.day)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day)/(1000*60*60*24 ));
Break;
Case "H ":
Case "Hour ":
Result = math. round (date. UTC (timecom1.year, timecom1.month-1, timecom1.day, timecom1.hour)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day, timecom2.hour)/(1000*60*60 ));
Break;
Case "min ":
Case "Minute ":
Result = math. round (date. UTC (timecom1.year, timecom1.month-1, timecom1.day, timecom1.hour, timecom1.minute)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day, timecom2.hour, timecom2.minute)/(1000*60 ));
Break;
Case "S ":
Case "second ":
Result = math. round (date. UTC (timecom1.year, timecom1.month-1, timecom1.day, timecom1.hour, timecom1.minute, timecom1.second)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day, timecom2.hour, timecom2.minute, timecom2.second)/1000 );
Break;
Case "Ms ":
Case "msecond ":
Result = date. UTC (timecom1.year, timecom1.month-1, timecom1.day, timecom1.hour, timecom1.minute, timecom1.second, timecom1.msecond)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day, timecom2.hour, timecom2.minute, timecom2.second, timecom1.msecond );
Break;
Case "W ":
Case "Week ":
Result = math. round (date. UTC (timecom1.year, timecom1.month-1, timecom1.day)-date. UTC (timecom2.year, timecom2.month-1, timecom2.day)/(1000*60*60*24) % 7;
Break;
Default:
Result = "invalid ";
}
Return (result );
}