What is the definition of the Events API cursor query parameter

The cursor query parameter looks like this: ‘0:0:0’. For sequential Events API requests, the Links header increments by (100) the middle element of the cursor. I can intuit the middle element indicates the start page in the remaining available events. What do the first and third elements do? For the Issues API the first element represents a starting timestamp. However that does not appear to be the case for the Events API. Any help/comments/suggestions would be appreciated. Thank you.