My project team has uncovered a bug in the TimePicker control (UI5 version 1.36.9).
Our app has a language link that changes the culture setting for the entire app, via sap.ui.getCore().getConfiguration().setLanguage()
The TimePicker control has one component that is not localising when the language model is changed - the AM/PM component (Vorm./Nachm in Deutsch).
The DatePicker for example functions perfectly, adjusting month names from May to Mai etc.
To be clear, TimePicker works in English on English-first devices, and in Deutsch on Deutsch-first devices. The label is not updating when the Core Language setting is changed, so it probably is not bound to an i18n model.
We kindly request this is escalated to the UI5 development team at SAP.