JavaScript getMonth function is one of the Date Functions, which returns the month number of a given date. This getMonth function returns the Month number starting at 0 (January) and ending at 11 (December).
JavaScript getMonth Example
We use the get Month to return the month number (starts at 0 and ends at 11) in the current date and time.
<!DOCTYPE html> <html> <head> <title> JavaScriptGetMonthFunction </title> </head> <body> <h1> JavaScriptgetMonthFunctionExample </h1> <script> var dt = Date(); document.write("Date and Time : " + dt); document.write("Month Number using getMonth(): " + dt.getMonth()); </script> </body> </html>

This JavaScript get Month example returns the Month Number from the custom date.
<!DOCTYPE html> <html> <head> <title> JS </title> </head> <body> <h1> Example </h1> <script> var dt = Date("January 12, 2016 10:09:34"); document.write("Date and Time : " + dt); document.write("Month Number : " + dt.getMonth()); </script> </body> </html>
Example
Date and Time: Tue Jan 12 2016 10:09:34 GMT+0530 (Indian Standard Time)
Month Number : 0
getMonth Example 2
In this JavaScript getMonth Function example, we extract the month from the custom year (I mean, without month or day).
<!DOCTYPE html> <html> <head> <title> JS </title> </head> <body> <h1> Example </h1> <script> var dt = Date("2016 10:09:34"); document.write("DateTime : " + dt); document.write("Month Number : " + dt.getMonth()); </script> </body> </html>
Example
DateTime: Fri Jan 01 2016 10:09:34 GMT+0530 (Indian Standard Time)
Month Number : 0