According to your description, does the CDateTimeCtr display as shown below:
And if you want the CDateTimeCtr to display as shown below:
If so, I suggest you could try to enable Visual Styles.
You could add the following compiler directive to your source code:
#pragma comment(linker,"\"/manifestdependency:type='win32' \
name='Microsoft.Windows.Common-Controls' version='126.96.36.199' \
processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
For more details, I suggest you could refer to the Doc:Enabling Visual Styles.