String representation of dates in GridDateTimeColumn is wrong in the FilterExpression when using Between filter.
The correct format should be ISO 8601:
([CreateDate] >= '2013-06-22T00.00.00') AND ([CreateDate] <= '2013-06-22T23.59.59'
Posted on:29 Jan 2018 09:56
This is the built-in behavior of RadGrid and it is not planned to change, because it may introduce some serious breaking changes related to the filtering functionality of the grid.
For additional information, please check the explanation provided in the following post: