Reference to the daysInMonth() function
   
    
    
Summary
daysInMonth(<timeZone> [,<tsExpression])
Returns the number of days in a month for the timestamp of the specified time zone. The values returned are integer only and are in the range 28-31.
Parameters
| Parameter | Description | 
|---|---|
| timeZone | 
String identifier or alias for a time zone, such as "US/Pacific". Names are case sensitive and must be enclosed in quotes. For a list of valid time zone identifiers and their aliases, see  http://joda-time.sourceforge.net/timezones.html.
 | 
| tsExpression | Optional expression to which you want to apply this function. | 
Description
The daysInMonth() standard time function returns number of days in a month for the timestamp of the specified time zone. The values returned are integer only and are in the range 28-31.
You can optionally pass in an expression.