Getting timestamp from mongodb id

How do I get the timestamp from the MongoDB id?

Answer

The timestamp is contained in the first 4 bytes of a mongoDB id (see: http://www.mongodb.org/display/DOCS/Object+IDs).

So your timestamp is:

timestamp = _id.toString().substring(0,8)

and

date = new Date( parseInt( timestamp, 16 ) * 1000 )