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tl;dr: store timestamps as timezone-aware types, use DATE for calendar values, and set your project timezone to the zone you report in.

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Timezone conversion

Lightdash converts the timezones of your data from their source timezone to a report timezone:
  • Source timezone is the timezone of the raw data. It is defined in your warehouse, data types, modelling, and connection settings.
  • Report timezone is the timezone you want to see in your results. It is defined by the project/user preferences, and specific chart/dashboard configuration.

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Pick the right column types in your warehouse

Store your event timestamps as timezone-aware types. They unambiguously identify a moment in time and require no extra configuration. If you choose a naive timestamp it’s timezone will be assumed to be in UTC unless you have configured the default data timezone.

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Use DATE only for calendar values

If a column represents a calendar date rather than a moment in time, store it as DATE. Lightdash treats DATE columns as fixed calendar dates and never shifts them: 2024-03-15 stays 2024-03-15 regardless of the project timezone. Use DATE for values like:
  • A user’s date of birth
  • A subscription start date
  • An anniversary
  • A fiscal-period boundary
DATE is not what you want for event timestamps. Don’t store dates as strings. A value like '2024-03-15' in a VARCHAR column is opaque to both the warehouse and Lightdash: sorting and range filters break, and every operation needs a cast. Convert string dates to a proper DATE or TIMESTAMP type in your dbt model.

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Configure your connection

For timestamps without timezones (naive timestamps), we assume they follow the default data timezone. You can configure this in your warehouse connection settings:
Data timezone field in warehouse connection advanced settings
  • If all your naive timestamps are in UTC (very common, since most ELT pipelines normalize to UTC): leave it as UTC.
  • If your naive timestamps are in a single non-UTC zone (e.g. an on-prem system that logs in local time): set the data timezone to that zone. Lightdash will interpret naive values as being in that zone.
  • If your naive timestamps have a mix of timezones - we currently don’t support overriding the timezone on a per-column level. Reach out to the team if you have a use case. If it’s an option, consider re-modelling your data in a timezone-aware type.

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Configure your project timezone

In Project settings → Timezone, pick the zone you want reports to use. Lightdash will convert all reports from the raw data timezone into the project timezone. This is the zone in which:
  • Timestamps are displayed in tables, on chart axes, and in exports.
  • “Today” and “yesterday” are computed in relative date filters.
  • Data is bucketed in a per-day grouped bar chart.
Project query timezone field in Project Settings
By default the project timezone is UTC, which means all reports in Lightdash default to showing results in UTC. The project timezone can be customised per chart or user.

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Opt a column out of timezone conversion

Most columns don’t need annotations. The main exception is system or audit columns where you want the raw stored value displayed, with no shift to the project timezone:
Use cases: audit logs, system timestamps, pre-converted values. The column renders exactly what the warehouse stores. DATE columns need no annotation. If you declare a column as type: date, Lightdash treats it as a calendar value with no timezone applied, and renders it as-is.

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Override a column timestamp domain

Lightdash reads whether a timestamp column is timezone-aware or naive from your warehouse catalog, so you don’t usually need to set this. Override it when the warehouse type doesn’t match how the data is stored, for example a TIMESTAMP_NTZ column that already holds UTC instants. Set timestamp_domain to aware or naive:
The YAML value wins over the catalog. It’s ignored on dimensions with custom sql and on additional dimensions, since the expression may change the domain. Interval children (_day, _month, …) inherit from their base.

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Naming conventions

Lightdash doesn’t enforce naming, but consistent suffixes make a model easier to read:
  • ..._at for timezone-aware timestamps (e.g., created_at, purchased_at).
  • ..._date for calendar DATE columns (e.g., signup_date, effective_date).
  • ..._at_utc for columns you’ve explicitly marked convert_timezone: false.

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Calendar dates vs timestamps: what shifts

Whether a column moves with the chart’s timezone depends on its type, not its name:
  • TIMESTAMP columns identify a moment in time, so they shift into the resolved timezone.
  • DATE columns are calendar values with no clock, so they never shift. 2024-03-15 stays 2024-03-15 for every viewer.
The same rule applies to a time interval built from a column. A day, week, or month grouping of a timestamp produces a calendar value, so its buckets move with the timezone. An hour-or-finer grouping stays a timestamp. You can see which is which before you build. The dimension list shows an indicator next to each date and time dimension. Hover it for the detail:
Timezone indicator in the dimension list: hovering a date dimension shows 'Calendar date, not affected by the chart's timezone'

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Verify your setup

Before building dashboards, run a quick smoke test:
  1. Open Explore on a model with a known timestamp column.
  2. Group by that dimension at Day granularity.
  3. Compare a few rows against the raw warehouse data.
If the dates match what you’d expect for your project timezone, you’re set. If they’re off by a fixed amount, the connection’s data timezone is the first thing to check. Once your data and project are configured, Timezones in daily use covers how each chart resolves its timezone and how filters, dashboards, and scheduled deliveries behave.