In today’s data-driven world, understanding time zones in Snowflake is crucial for accurate reporting, analytics, and scheduling. Whether you’re managing data for teams in New York, London, Tokyo, or Sydney, knowing how Snowflake handles time zones ensures your queries return correct results and your dashboards reflect real-time insights. Snowflake Timezone: The Ultimate Guide for Global Users.
This guide will take you from beginner to advanced levels, covering Snowflake’s timezone settings, session management, UTC usage, and best practices for global organizations.
Understanding Time Zones in Snowflake
Snowflake stores timestamps in UTC internally. However, it provides flexibility to display and manipulate times in different time zones for queries and reports.
Key Concepts
- UTC (Coordinated Universal Time): The standard reference time. Snowflake stores all TIMESTAMP_NTZ (no time zone) and TIMESTAMP_TZ (with time zone) data internally in UTC.
- TIMESTAMP Types:
- TIMESTAMP_NTZ: No timezone information. Stored as-is; interpreted in the session time zone.
- TIMESTAMP_LTZ: Stored in UTC, displayed according to the session’s time zone.
- TIMESTAMP_TZ: Includes explicit time zone info; automatically converted when queried.
- Session Time Zone: Determines how timestamps are displayed during queries. It can differ from your local time or account default.
Why Time Zones Matter in Snowflake
Incorrect timezone handling can lead to:
- Misaligned financial reports across regions.
- Confusing analytics dashboards for international teams.
- Errors in data pipelines involving scheduled events.
For example, a sales report generated in New York at 8 AM EST will appear differently if viewed by a team in Tokyo (UTC+9) without proper timezone conversion.
Global Time Zone Settings in Snowflake
1. Account-Level Time Zone
Your Snowflake account has a default timezone. This serves as a fallback if session timezone is not set.
Example:
ALTER ACCOUNT SET TIMEZONE = 'America/New_York';
2. Session-Level Time Zone
Set per user session to display timestamps in their local time zone.
Example:
ALTER SESSION SET TIMEZONE = 'Asia/Tokyo';
3. Object-Level Time Zone
While creating timestamps with time zone, specify explicit TZ:
CREATE TABLE sales (
sale_id INT,
sale_time TIMESTAMP_TZ
);
INSERT INTO sales VALUES (1, '2026-01-27 08:00:00+09:00');
Common Snowflake Timestamp Types Explained
| Type | Stored As | Display Behavior | Best Use Case |
|---|---|---|---|
| TIMESTAMP_NTZ | As-is | Interpreted in session time zone | Raw data ingestion |
| TIMESTAMP_LTZ | UTC | Converts to session time zone for queries | Regional reporting |
| TIMESTAMP_TZ | UTC + TZ info | Maintains time zone info | Multi-region events or logs |
Expert Tip: For multi-region systems, prefer TIMESTAMP_LTZ or TIMESTAMP_TZ to avoid conversion errors. Snowflake Timezone: The Ultimate Guide for Global Users.
Converting Time Zones in Snowflake
Snowflake provides functions for converting timestamps between zones:
1. CONVERT_TIMEZONE
SELECT CONVERT_TIMEZONE('America/New_York', 'Asia/Tokyo', CURRENT_TIMESTAMP);
- Converts a timestamp from New York time to Tokyo time.
- Handles Daylight Saving Time automatically.
2. CURRENT_TIMESTAMP with Session Time Zone
ALTER SESSION SET TIMEZONE = 'Europe/London';
SELECT CURRENT_TIMESTAMP;
- Displays current time in the session’s timezone.
Best Practices for Managing Time Zones in Snowflake
- Store All Timestamps in UTC: Ensures consistency across regions.
- Use TIMESTAMP_TZ for Global Events: Retains original timezone info.
- Set Session Time Zone for Each User: Personalizes query results.
- Always Convert for Reporting: Use
CONVERT_TIMEZONE()for dashboards across multiple regions. - Document Account & Session Defaults: Avoid confusion in multi-team environments.
Daylight Saving Time and Snowflake
DST can affect timestamp accuracy if overlooked. Snowflake handles DST automatically for named time zones like 'America/New_York' or 'Europe/London'. Avoid using numeric offsets (like +05:30) if DST adjustments are required.
Practical Examples
Example 1: Sales Dashboard Across Regions
SELECT
sale_id,
sale_time,
CONVERT_TIMEZONE('UTC', 'America/Los_Angeles', sale_time) AS pacific_time,
CONVERT_TIMEZONE('UTC', 'Asia/Tokyo', sale_time) AS tokyo_time
FROM sales;
- Allows teams in LA and Tokyo to view the same sales data in local time.
Example 2: Scheduled Data Loads
ALTER SESSION SET TIMEZONE = 'UTC';
INSERT INTO analytics_load VALUES (CURRENT_TIMESTAMP);
- Ensures consistent timestamps across servers in multiple continents.
Advanced Tips for Snowflake Time Zones
- Use Named Time Zones Over Numeric Offsets:
'Asia/Kolkata'adjusts for DST,+05:30does not. - Leverage Session Variables for Multi-Region Scripts:
SET region = 'America/New_York';
SELECT CONVERT_TIMEZONE($region, 'Asia/Tokyo', CURRENT_TIMESTAMP);
- Audit Logs: Always include timestamp with time zone to avoid confusion.
Frequently Asked Questions (FAQ)
Q1: What is the difference between TIMESTAMP_NTZ and TIMESTAMP_TZ?
A: TIMESTAMP_NTZ has no timezone info, while TIMESTAMP_TZ includes explicit time zone for conversion.
Q2: Should I store data in UTC or local time?
A: Always store in UTC to maintain consistency; convert for display using session or query functions.
Q3: How do I handle DST in Snowflake?
A: Use named time zones like 'America/New_York'—Snowflake automatically adjusts for DST.
Q4: Can I change the time zone for a specific user?
A: Yes, set a session-level time zone using ALTER SESSION SET TIMEZONE = '<zone>'.
Q5: How do I show current time in a specific time zone?
A: Use CONVERT_TIMEZONE() or set session time zone and call CURRENT_TIMESTAMP.
Actionable Checklist for Snowflake Time Zone Management
- Store all timestamps in UTC.
- Use TIMESTAMP_TZ for global events.
- Set session timezone per user session.
- Convert timestamps for dashboards with
CONVERT_TIMEZONE(). - Document all account and session defaults.
- Prefer named time zones for DST handling.
- Audit multi-region data with time zone metadata. Snowflake Timezone: The Ultimate Guide for Global Users.
Conclusion
Mastering Snowflake time zones ensures accurate analytics, global collaboration, and seamless operations. By understanding timestamp types, session settings, and conversion functions, you can confidently manage data for teams in New York, London, Tokyo, Sydney, Mumbai, and beyond.
Proper time zone management in Snowflake reduces errors, improves reporting accuracy, and ensures your global data strategy runs smoothly.






Leave a Reply