Hi Andreas,
Thanks for your interest in Syncfusion Products.
We have created sample based on your request which can be downloaded from the below link.
In this below sample, the property 'Pattern' is set to 'SortableDateTime'. This will display the time 24 hour mode.
Please let us know if you have any queries.
Regards,
Jegan Raj M
DateTimeEditSample_9244de77.zip