how to extract difference between timestamps
You can use Windows Functions which provides calculation across a set of table rows that are somehow related to the current row. The list of functions are in General-Purpose Window Functions section of the documentation and The lead() and lag() functions are answer of your question. Your query will should like this;

SELECT *,
  "RecognitionTimestamp" - lag("RecognitionTimestamp") OVER(ORDER BY "RecognitionTimestamp") AS delta_previous,
  lead("RecognitionTimestamp") OVER(ORDER BY "RecognitionTimestamp") - "RecognitionTimestamp" AS delta_next
FROM "table" 
WHERE
  "RecognitionTimestamp" &gt;= '2018-10-03 00:00:00' AND 
  "RecognitionTimestamp" &lt;= '2018-10-04 9:00:00'