What is the timestampSpec format for Unix timestamp in Ingestion Spec?

Hi,

I have data with the following timestamp of unix time.

“unix_time”:1501609493000,"

what is the timestampSpec format should i use? Will “auto” be sufficient?

"timestampSpec" : {
        "column" : "unix_time",
        "format" : "auto"
      },

Thanks in advance

Use format of “posix” will work.