I am afraid that the Scheduler widget would not allow you to define a template for the resize visualization. Having that said, in order to display a 24 hours clock, I would suggest you use a Kendo culture which has that format as its default. For example, the en-GB culture is such:
As per the custom text, that could not be added to the resize element.
Here you will find a Dojo sample implementing the above. Keep in mind that the change of the culture may also affect other parts of the Kendo widgets.
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