The last transaction in blocks 219882, 219888, and 219892 don't have a timestamp. And by last transaction I mean the last transaction shown in the json file.
I find this to be a bit odd. Does anyone know why this has occurred?
There is no timestamp field in bitcoin transactions. BC.I timestamps the transaction when it comes to this service for a very first time. You should not use this value, because it can be quite incorrect/irrelevant.
I think that the last transactions in these blocks have not seen by BC.I in "wild" form. BC.I discovered them when they come within a block. So, it is a small bug on BC.I - it does not shows you timestamp for some txs.
Just live with it.