There seems to be no way to retrieve the system date of the mongodb server. This is a problem if the client time is not synched with the server (which it will usually not be). Currently the only option is to use a new Date() from either javascript on the client or the language of the driver, or possibly using a $where.

This could easily be solved by allowing $currentDate to be used in queries rather than just in updates.

The problem with not having this is, for example, on a findAndModify when a Date or Timestamp value is part of the query. It would be best to have the corresponding date field be from a uniform base, such as what $currentDate is, namely the system time of the server. Consider when querying against an expiration time, it is somewhat useless from multiple servers, with only gross time intervals making sense.