The CRM WF Date/Time Utilities are three custom workflow activities that can be used to extend CRM's limitations of Date/Time fields. The following is a description of each of the custom workflow activities.
Get Date Parts
This utility will take in a Date/Time field and return all the parts of the Date/Time such as the day, month, year, hour, minute, second, and millisecond.
Set Date Parts
This utility will take in a Date/Time field and allow a specific part of the Date/Time field to be overwritten. For example, you could always set a Date/Time to 5pm by passing in 5 for the "Hour" parameter of this workflow activity.
Add Date Parts
This utility is similar to SetDateParts but instead of overriding a part of the Date/Time field, it will add a date part onto the existing Date/Time field. In the above example, if you pass in 5 for the "Hour" parameter, it will add 5 hours to the existing Date/Time rather than setting the Time to 5pm.
See the documentation tab for examples on how to use the three utilities.