By default when you construct query using Camlex.NET attribute IncludeTimeValue is not used. As MSDN documentation states:
Optional Boolean. Specifies to build DateTime queries based on time as well as date. If you do not set this attribute, the time portion of queries that involve date and time are ignored.
In most cases there is no need to include time part in queries when you are looking for list items and your queries will work just fine. In my project it was essential to use date and time at the same time because millions of dollars depend upon several seconds.
Enough teory. It is time for practice. Continue reading