MongoDB Date range query for past hour

db.entity.find({ $and:[
    {
    "timestamp": {
        $gte: new Date(ISODate().getTime() - 1000 * 60 * 60)
    }}, 
    { 
    "timestamp": {
        $lte: ISODate()
    }}
]})

Hope this helps...

db.coll.find({
    "time": { // 60 minutes ago (from now)
        $gte: new Date(ISODate().getTime() - 1000 * 60 * 60)
    }
})