Found a parsing error.
This is the output that confirms that the code still works:
old start = 934948800000
new start = 934985539332
differenceDays = 0
old end = 1337659200000
new end = 1337695939332
differenceDays = 0
instance Name old:R20111105101219
instance Name new:R20111105101219
date to z old:20111205101219Z
date to z new:20111205101219Z
old = 1021569630000
new = 1021569630334
old = 1021569630000
new = 1021569630334
Attached are the two files that produce that output;