​ To learn more, see the sources I considered: [[1] Connect Retell voice agents to custom telephony](https://docs.retellai.com/deploy/custom-telephony) [[2] Import Phone Number](https://docs.retellai.com/api-references/import-phone-number) [[3] AI in SIP Calling & Telephony Solutions | Retell AI](https://www.retellai.com/blog/integrating-ai-with-sip-trunking-and-modern-telephony) ​

### Answer Yes, you can use one SIP trunk for multiple numbers and multiple voice agents. [(1) ]() [(2) ]() When using Elastic SIP Trunking (the recommended method) , you set up a single SIP trunk with your telephony provider and then import multiple phone numbers into Retell that all use the same termination URI from that trunk. For each imported number, you can bind different agents: [(2) ]() - **Inbound agents**: Assign specific agents with weights to handle incoming calls on each number - **Outbound agents**: Assign specific agents with weights for outbound calls from each number The import process requires you to provide the termination URI that identifies your elastic SIP trunk (used for outbound calls) , and you can assign unique agent IDs to each number. [(3) ]() This means one SIP trunk can support multiple numbers, with each number potentially connected to different AI agents based on your configuration. [(1) ]() [(2) ]()

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer You can handle different timezones using dynamic variables and the Book Appointment Cal tool. [(1) ]() [(2) ]() When configuring the Book Appointment Cal tool in your agent, you specify the timezone parameter: [(2) ]()

json
{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "America/Los_Angeles"
}

For dynamic timezone handling, you can: 1. Pass timezone as a dynamic variable when creating the call, then reference it in your agent's logic [(1) ]() [(2) ]() 2. Use system default dynamic variables like

{{current_time_[timezone]}}

to get the current time in any timezone (e.g.,

{{current_time_Australia/Sydney}}

or

{{current_time_America/New_York}}

) [(3) ]() 3. Include timezone information in your prompt using dynamic variables to ensure the agent books appointments in the correct timezone [(4) ]() The key is injecting timezone data into the call context at call creation using the

variables

field, ensuring the agent has the correct timezone information before attempting to book. **

​ To learn more, see the sources I considered: [[1] Update Retell LLM](https://docs.retellai.com/api-references/update-retell-llm) [[2] Create Retell LLM](https://docs.retellai.com/api-references/create-retell-llm) [[3] Platform Changelogs | Retell AI](https://www.retellai.com/changelog) [[4] GHL + Make + Retell](https://community.retellai.com/t/ghl-make-retell/806) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer No, this is not correct. There's a timezone mismatch issue occurring. Based on the sources, the timezone in Cal.com and in Retell AI need to match for the booking feature to work correctly. [(1) ]() Since your Cal.com is set to NZST but you're booking from Perth (AWST) , the system is likely experiencing the timezone confusion you're describing. The issue is that when you requested 5am Perth time, the agent should have converted this to the equivalent NZST time (which would be 9am NZST, not 2pm NZST) . The 2pm NZST booking you received doesn't match your 5am Perth request. To fix this: 1. **Ensure timezone consistency**: The timezone parameter in your Book Appointment Cal tool configuration should match your Cal.com timezone setting. [(2) ]() [(3) ]() For example:

json
{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "Pacific/Auckland"
}

[(3) ]() 2. Pass the user's timezone as a dynamic variable when creating the call so the agent knows to convert Perth time to NZST correctly. [(2) ]() [(3) ]() 3. Configure the agent's timezone setting in the agent configuration to handle timezone conversions properly. [(4) ]() The core issue is that timezone mismatches between Retell AI and Cal.com prevent proper booking functionality. [(1) ]()

​ To learn more, see the sources I considered: [[1] Discord message from @shuvonomore on 2025-03-21](https://discord.com/channels/1186424376300679209/1186462578310910112/1352582367507906620) [[2] Update Retell LLM](https://docs.retellai.com/api-references/update-retell-llm) [[3] Create Retell LLM](https://docs.retellai.com/api-references/create-retell-llm) [[4] Get Agent Versions](https://docs.retellai.com/api-references/get-agent-versions) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer Yes, you should set your Retell booking timezone to match Cal.com (

Pacific/Auckland

) . To handle bookings in the caller's timezone, you can use dynamic variables and prompt instructions. [(1) ]() [(2) ]() [(3) ]() Here's the approach: 1. Configure your Book Appointment Cal tool with your Cal.com timezone: [(2) ]() [(3) ]()

json
{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "Pacific/Auckland"
}

[(2) ]() , [(3) ]() 2. Use dynamic variables to capture and convert the user's timezone: [(1) ]() You can pass the user's timezone as a dynamic variable when creating the call using `retell_llm_dynamic_variables`:

json
{
  "user_timezone": "Australia/Perth"
}

3. In your agent prompt, instruct it to ask for location and handle timezone conversion: [(1) ]() [(2) ]() [(3) ]() Add instructions like this to your

general_prompt

or `state_prompt`: [(2) ]() [(3) ]() - Ask the user what state or city they're calling from [(1) ]() - Use that information to determine their timezone - When they request a time (like "5am my time") , convert it to Pacific/Auckland time before booking - You can reference

{{user_timezone}}

in your prompt if you pass it as a dynamic variable The agent will handle the timezone math in conversation, ensuring that when someone in Perth says "5am," it books the correct equivalent time in your NZST Cal.com calendar. [(1) ]() [(2) ]() [(3) ]()

​ To learn more, see the sources I considered: [[1] Dynamic variables: personalize Retell agent calls](https://docs.retellai.com/build/dynamic-variables) [[2] Update Retell LLM](https://docs.retellai.com/api-references/update-retell-llm) [[3] Create Retell LLM](https://docs.retellai.com/api-references/create-retell-llm) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.

### Answer I can help you draft a message to Conductor AI to verify the timezone configuration changes. Here's what you can send: --- Message to Conductor AI: "Hey Conductor AI, I need you to review and confirm the timezone configuration changes you just made for the Retell AI appointment booking system. Please double-check the following: 1. Book Appointment Cal Tool Configuration: [(1) ]() - Verify that the

timezone

parameter in the Book Appointment Cal tool is set to

"Pacific/Auckland"

to match my Cal.com calendar - Confirm the configuration looks like this:

json
{
  "type": "book_appointment_cal",
  "name": "book_appointment",
  "description": "Book an annual check up.",
  "cal_api_key": "cal_live_xxxxxxxxxxxx",
  "event_type_id": 60444,
  "timezone": "Pacific/Auckland"
}

2. Prompt Instructions for User Timezone Handling: [(2) ]() - Confirm you've added instructions in the agent prompt (

general_prompt

or

state_prompt

) that tell the agent to: [(1) ]() - Ask the user what state/city they're calling from - Identify their timezone based on their location - Convert their requested time to Pacific/Auckland (NZST) before booking - Handle the timezone conversion accurately (e.g., Perth 5am = Auckland 9am) 3. Dynamic Variable Support (if applicable) : [(2) ]() - If you've set up dynamic variables for timezone handling, confirm that

{{user_timezone}}

or similar variables are properly referenced in the prompt Please review these changes and let me know if everything is configured correctly. I want to ensure that when someone in Perth says '5am my time,' it books the correct equivalent time in my NZST Cal.com calendar." --- This message asks Conductor AI to verify the specific technical requirements for proper timezone handling in Retell AI. [(1) ]() [(2) ]()

​ To learn more, see the sources I considered: [[1] Update Retell LLM](https://docs.retellai.com/api-references/update-retell-llm) [[2] Dynamic variables: personalize Retell agent calls](https://docs.retellai.com/build/dynamic-variables) ​

Feel free to tag @AI Evy with additional questions. I also appreciate feedback, it helps me improve.