Originally Posted by
David-A
Confirmed, you want a #423.
It actually starts from 0343(!) - if your starting from Harlington Corner towards T5.
Journey time is 13 mintues, so any of the following should get you there for 0600, again this is from harlington corner.
M-F: 0343, 0413, 0443, 0513, 0530, 0540.
S/S: 0343, 0413, 0443 0513, 0544.
Yes, forget the other options, the 423 is easy and free!