var d = new Date(),
hour = d.getHours(),
min = d.getMinutes(),
month = d.getMonth(),
year = d.getFullYear(),
sec = d.getSeconds(),
day = d.getDate();
Submission.find({
/* First Case: Hour */
created: { $lt: new Date(), $gt: new Date(year+','+month+','+day+','+hour+','+min+','+sec) } // Get results from start of current hour to current time.
/* Second Case: Day */
created: { $lt: new Date(), $gt: new Date(year+','+month+','+day) } // Get results from start of current day to current time.
/* Third Case: Month */
created: { $lt: new Date(), $gt: new Date(year+','+month) } // Get results from start of current month to current time.
/* Fourth Case: Year */
created: { $lt: new Date(), $gt: new Date(year) } // Get results from start of current year to current time.
})