Saving Content with Time field when Time field is using its default value (12:00) would result in empty value for this field (if Time field is required, the form will not submit).

Steps to reproduce
1. Clean installation of eZ Platform 2.5
2. Create a new ContentType Content With Time containing only one field: Time time. Leave all set to the defaults.
3. Create a new Content of type Content With Time.
4. Click on time field, Time Picker will show, and field will get value of 12:00. Without changing anything press Publish button.

Result
Content will be published with empty time field.

Hint: Changing time in Time Picker (even back to 12:00) will allow the value of the time field to be saved properly.