Jinja Templates in Workflows

Jinja templates allow you to dynamically generate content in your workflows using variables, expressions, and built-in functions. This guide covers how to use Jinja templates, with a focus on date and time operations.

Basic Syntax

Jinja templates use double curly braces {{ }} for expressions and {% %} for control structures:

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{{ variable_name }}
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{{ workflow_state.some_field }}
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{{ "Hello " + user_name }}

For more information on accessing workflow state variables, see Workflow Logic & State > State Management.

Date and Time Operations

Available Utilities

The following datetime utilities are automatically available in all Jinja templates:

• datetime - Python’s datetime class for creating and manipulating dates/times
• timezone - For working with UTC timezone
• ZoneInfo - For working with specific timezones (e.g., Pacific, Eastern)

Getting Current Time

Current UTC Time

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{{ datetime.now(timezone.utc) }}

Current Pacific Time

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{{ datetime.now(ZoneInfo("America/Los_Angeles")) }}

Other Common Timezones

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{{ datetime.now(ZoneInfo("America/New_York")) }}      {# Eastern #}
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{{ datetime.now(ZoneInfo("America/Chicago")) }}        {# Central #}
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{{ datetime.now(ZoneInfo("America/Denver")) }}         {# Mountain #}
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{{ datetime.now(ZoneInfo("America/Anchorage")) }}      {# Alaska #}
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{{ datetime.now(ZoneInfo("Pacific/Honolulu")) }}       {# Hawaii #}

Formatting Dates and Times

Use the strftime() method to format datetime objects:

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{# Full date and time #}
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{{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%A, %B %d, %Y at %I:%M %p') }}
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{# Output: "Tuesday, March 02, 2024 at 10:30 AM" #}
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{# Date only #}
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{{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%Y-%m-%d') }}
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{# Output: "2024-03-02" #}
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{# Time only #}
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{{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%I:%M %p') }}
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{# Output: "10:30 AM" #}
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{# ISO format #}
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{{ datetime.now(timezone.utc).isoformat() }}
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{# Output: "2024-03-02T17:30:00+00:00" #}

Common strftime Format Codes

Converting Between Timezones

Convert a UTC datetime to Pacific time:

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{{ datetime.now(timezone.utc).astimezone(ZoneInfo("America/Los_Angeles")) }}

Creating Specific Dates

Create a datetime for a specific date and time:

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{# March 15, 2024 at 10:30 AM Pacific #}
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{{ datetime(2024, 3, 15, 10, 30, 0, tzinfo=ZoneInfo("America/Los_Angeles")) }}
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{# Today at midnight UTC #}
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{{ datetime.now(timezone.utc).replace(hour=0, minute=0, second=0, microsecond=0) }}

Date Arithmetic

While Jinja doesn’t have built-in date arithmetic, you can work with timestamps:

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{# Get timestamp #}
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{{ datetime.now(timezone.utc).timestamp() }}
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{# Format relative time (requires custom logic or use of workflow state variables) #}

Common Use Cases

Including Current Date in Messages

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Today is {{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%A, %B %d, %Y') }}.
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The current time is {{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%I:%M %p') }}.

Generating Timestamps for Logs

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Log entry at {{ datetime.now(timezone.utc).isoformat() }}: {{ message }}

Time-Sensitive Conditional Logic

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{% set pacific_time = datetime.now(ZoneInfo("America/Los_Angeles")) %}
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{% set hour = pacific_time.hour %}
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{% if hour >= 9 and hour < 17 %}
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Business hours message
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{% else %}
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After hours message
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{% endif %}

Formatting Dates from Variables

If you have a date string in your workflow state, you can parse and format it:

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{# Assuming created_at is an ISO format string in your workflow state #}
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{{ datetime.fromisoformat(created_at).strftime('%B %d, %Y') }}

Available Variables

In addition to datetime utilities, your templates have access to:

• Workflow State Variables: All variables from previous blocks in your workflow

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  {{ block_name.output }}
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  {{ user_input }}

• Global Variables: Pre-formatted date/time strings (for convenience)

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  {{__exp_global.current_date}}           {# "Tuesday, March 02, 2024" #}
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  {{__exp_global.current_time}}           {# "10:30 AM" (local system time) #}
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  {{__exp_global.current_datetime}}       {# "Tuesday, March 02, 2024 at 10:30 AM" #}
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  {{__exp_global.current_time_pacific}}   {# "10:30 AM" #}
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  {{__exp_global.current_time_eastern}}   {# "1:30 PM" #}
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  {{__exp_global.current_time_utc}}        {# "5:30 PM" #}

For a complete list of global variables, see Workflow Logic & State > Global Variables.

• Environment Variables: Access environment variables using _env

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  {{ _env.API_KEY }}

For more information, see Environment Variables.

Examples

Example 1: Email with Timestamp

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Subject: Report Generated - {{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%B %d, %Y') }}
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Your report was generated on {{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%A, %B %d, %Y at %I:%M %p %Z') }}.

Example 2: Dynamic Greeting Based on Time

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{% set pacific = datetime.now(ZoneInfo("America/Los_Angeles")) %}
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{% set hour = pacific.hour %}
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{% if hour < 12 %}
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Good morning!
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{% elif hour < 17 %}
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Good afternoon!
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{% else %}
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Good evening!
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{% endif %}

Example 3: ISO Timestamp for API Calls

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{
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  "timestamp": "{{ datetime.now(timezone.utc).isoformat() }}",
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  "message": "{{ user_message }}"
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}

Example 4: Combining with Workflow Variables

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Task completed by {{ user_name }} on {{ datetime.now(ZoneInfo("America/Los_Angeles")).strftime('%B %d, %Y at %I:%M %p') }}.
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Status: {{ task_status }}
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Notes: {{ task_notes }}

Tips and Best Practices

1. Always specify timezones: When working with dates/times, explicitly specify the timezone to avoid ambiguity

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   {# Good #}
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   {{ datetime.now(ZoneInfo("America/Los_Angeles")) }}
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   {# Avoid - no timezone #}
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   {{ datetime.now() }}

2. Use UTC for storage/logging: Use UTC when storing timestamps or logging events

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   {{ datetime.now(timezone.utc).isoformat() }}

3. Format for display: Use timezone-aware datetimes when displaying to users

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   {{ datetime.now(timezone.utc).astimezone(ZoneInfo("America/Los_Angeles")).strftime('%I:%M %p') }}

4. Test your templates: Verify your date/time formatting works as expected in your workflow preview

5. Choose the right tool: Use global variables for simple, pre-formatted dates. Use datetime utilities when you need custom formatting, timezone conversions, or calculations.

Additional Resources

• Workflow Logic & State - Learn about workflow state management and global variables
• Python datetime documentation
• Jinja2 template documentation
• strftime format codes reference