@Vapi @Vapi Support Bot @GeraDeluxer I’m building a German voice agent in Vapi and I’m facing an issue with time pronunciation in German. ##What works correctly When opening hours are hardcoded in the prompt, the pronunciation is correct and natural. For example: - Montag: 12:45 Uhr bis 18:00 Uhr - Samstag: 09:00 Uhr bis 13:00 Uhr Since these are already written in German, the agent speaks them correctly. ## The problem When the caller asks a general or dynamic time-related question, such as: - „Wie spät ist es?“ - „Wann schließen Sie heute?“ …the agent generates time using English-style logic, even though the response is in German. ### Examples of incorrect output - „dreizehn Uhr dreißig“ - „fünfzehn Uhr dreißig“ ### Expected (native German) output - „halb zwei“ - „Viertel nach eins“ - „Viertel vor vier“ This appears to be a time-format reasoning issue, not a TTS voice issue. ## Questions 1. Is there a recommended way in Vapi to enforce locale-specific (German) time formatting? 2. Are there any prompt patterns or built-in Vapi features that help reliably handle language-specific time pronunciation?

Thank you for the detailed description. To help pinpoint the best solution: Are you currently using any custom prompt instructions or replacements in your Vapi assistant to influence how dynamic times are phrased in German, or is it relying solely on the default model output? Sources: - [Voice formatting plan](https://docs.vapi.ai/assistants/voice-formatting-plan) - [Pronunciation dictionaries](https://docs.vapi.ai/assistants/pronunciation-dictionaries) - [Multilingual support](https://docs.vapi.ai/customization/multilingual)

It is relying on the default model output @Vapi Support Bot

To enforce native German time expressions, add explicit instructions to your system prompt. For example:

Bitte gib Uhrzeiten im deutschen Stil aus, z.B. „halb zwei“ statt „dreizehn Uhr dreißig“, „Viertel nach eins“ statt „dreizehn Uhr fünfzehn“.

Update your assistant's system prompt with this instruction to guide the model toward culturally correct time phrasing in German. This approach is recommended for handling locale-specific formatting according to the multilingual documentation. Source: - [Multilingual support](https://docs.vapi.ai/customization/multilingual)

Hey Hamza, there's no way for VAPI to control it; you have to do it via prompt engineering only. Specifically mentioned in the prompt to follow this, and give examples. Vapi give formatting plan, but for locale-specific time, it's hard because they don't follow exact rules.