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Date & Time Tools

OpenJarvis includes 4 date and time tools for getting the current time, doing date arithmetic, formatting dates, and calculating durations.

Tools

get_current_datetime

Get the current date and time in any timezone.

Parameters:

Parameter Type Default Description
timezone string "UTC" Timezone name (e.g. "America/New_York", "Asia/Tokyo")

Returns: ISO 8601 timestamp with weekday name.

Example prompts: 

> What time is it right now?
> What's the current time in Tokyo?
> What day of the week is it in New York?
> What time is it in London?

Common timezones: - UTC - America/New_York - America/Chicago - America/Los_Angeles - Europe/London - Europe/Paris - Asia/Tokyo - Asia/Shanghai - Australia/Sydney

date_arithmetic

Add or subtract days and hours from a date.

Parameters:

Parameter Type Default Description
date_str string required Starting date/datetime (ISO format: YYYY-MM-DD or YYYY-MM-DDTHH:MM:SS)
days integer 0 Days to add (negative to subtract)
hours integer 0 Hours to add (negative to subtract)

Returns: Resulting datetime as ISO 8601 string.

Example prompts: 

> What date is 30 days from today?
> My subscription started on 2024-01-15. When does it expire after 1 year?
> What was the date 90 days ago?
> Add 2 weeks to 2024-08-01

format_datetime

Format a date string in a human-readable format.

Parameters:

Parameter Type Required Description
date_str string yes Date string (ISO format)
fmt string yes Output format string (Python strftime)

Returns: Formatted date string.

Common format strings:

Format Example Output
%B %d, %Y August 15, 2026
%d/%m/%Y 15/08/2026
%m/%d/%Y 08/15/2026
%A, %B %d Saturday, August 15
%Y-%m-%d 2026-08-15
%I:%M %p 02:30 PM

Example prompts: 

> Format 2026-08-15 as "August 15, 2026"
> Display the date 2024-12-25 in European format (DD/MM/YYYY)
> Show 2024-03-14T15:00:00 in a readable format

days_between

Calculate the number of days between two dates.

Parameters:

Parameter Type Required Description
date_a string yes First date (ISO format: YYYY-MM-DD)
date_b string yes Second date (ISO format: YYYY-MM-DD)

Returns: Number of days between the dates (positive integer, order doesn't matter).

Example prompts: 

> How many days until Christmas (December 25)?
> How long has it been since 2024-01-01?
> How many days between my birthday on March 15 and the end of the year?
> How many days is a 90-day trial that started on 2024-06-01?

Usage Examples

Current Time in Timezone

oj> What time is it in Sydney right now?

  ↳ routing: generalist → knowledge
  ⚙ tool: get_current_datetime {"timezone": "Australia/Sydney"}
    → 2026-08-16T06:45:12 Sunday

It is currently **6:45 AM on Sunday, August 16** in Sydney, Australia.

Deadline & Days Between

oj> My project deadline is 2026-09-30. How many days from 2026-08-15 is that?

  ↳ routing: generalist → math
  ⚙ tool: days_between {"date_a": "2026-08-15", "date_b": "2026-09-30"}
    → 46

There are **46 days** remaining until September 30.

See Also