18-is-a-duration.md

title	version	signature
Is a Duration	1.6.0	moment.isDuration(obj);

To check if a variable is a moment duration object, use moment.isDuration().

moment.isDuration() // false
moment.isDuration(new Date()) // false
moment.isDuration(moment()) // false
moment.isDuration(moment.duration()) // true
moment.isDuration(moment.duration(2, 'minutes')) // true