Powershell recurse through a directory to third tier/level?

We have a file system that is broken down by >>\year\month\day\hour\minute and we want to get down to the third level (day) and do a measurement of all the children in that folder. Is this achievable through PowerShell?

Some samples I've been trying to tweak:

(get-childitem C:\Bulkloading\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1MB

(get-childitem C:\Bulkloading\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1GB

[Math]::round((get-childitem D:\rbs01\collab_ep001_c\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1GB,2)

Start

D:\RBS_Cache\

Stop Here

D:\RBS_Cache\2013\11\01

D:\RBS_Cache\2013\09

(get-childitem D:\RBS_Cache\2013\09\01\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1MB

(get-childitem D:\RBS_Cache\2013\09\02\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1MB

(get-childitem D:\RBS_Cache\2013\09\03\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1MB

(get-childitem D:\RBS_Cache\2013\09\04\ -Recurse | Measure-Object -Property Length -Sum ).Sum / 1MB

Trying to set a task schedule to run every day and find the new folder for that day. Every day it will look for that day's folder plus the days before. I want to see what the size increase is on a daily increment.