Thanks Eric and Pieter .its working fine now.
Are you inside a microflow? If so, you can create a BeginningOfDay variable and an EndOfDay variable, then use XPath to select all values >= $BeginningOfDay and <= $EndOfDay
See here for expressions you can use to create your variables.
What is it that you actualy want to retrieve, functionally?
If it is the first occurence in a day.
Use a retrieve like this.
$StartOfDay = 2014-10-28 00:00:00.000
$EndOfDay = addDays($StartOfDay,1)
[$StartOfDay <= MyFirstModule.A/createdDate and $EndOfDay > MyFirstModule.A/createdDate]
Make sure you sort the retrieve based on createdDate Ascending and set the retrieve on first only.