I want to send a query to the Google Search Appliance that includes date range criteria of a meta field (lets call it metaDate). For example: metaDate field between 01.01.2010 and 01.01.2015. How can i construct a query such like this?
Mohan's not entirely correct. You can perform range searches on any metadata attribute. This is different then the document date. See Google's Documentation for this.
Also you can create a dynamic navigation element and test the format yourself. Dynamic Navigation can be used to construct range searches.