This message was deleted.

I believe this has been seen with segmentGranularity of "all" and/or without using a missingValue for timestampSpec

I never used segmentGranularity "all", its all hour, day, month or year. And the default for a missing timestamp (if its not configured explicitly) is to use 0 = 1970-01-01T000000, are you saying that its not always the case and can sometimes result in a "weird" timestamp unless the missingValue is explicitly specified?

it could be that OR if you have a record with a "bad" TimeColumn.

The only cases where I have seen this is when the data was malformed coming in, which means some upstream process could be messing it up. You could always set early/late message rejection, but that may hide the problem. Any chance you can identify the source data for the records in question?