> ## Documentation Index > Fetch the complete documentation index at: https://elementary-more-explicit-webhook-instructions.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # freshness_anomalies `elementary.freshness_anomalies` Monitors the freshness of your table over time, as the expected time between data updates. Upon running the test, your data is split into time buckets (daily by default, configurable with the `time bucket` field), and then we compute the maximum freshness value per bucket for the last `training_period` (by default 14 days). The test then compares the freshness of each bucket within the detection period (last 2 days by default, controlled by the `detection_period` var), and compares it to the freshness of the previous time buckets. If there were any anomalies during the detection period, the test will fail. ### Test configuration *Required configuration: `timestamp_column`* *Default configuration: `anomaly_direction: spike` to alert only on delays.* {/* prettier-ignore */} 
  
    tests:
      -- elementary.freshness\_anomalies:
        timestamp\_column: column name
        where\_expression: sql expression
        anomaly\_sensitivity: int
        detection\_period:
          period: \[hour | day | week | month]
          count: int
        training\_period:
          period: \[hour | day | week | month]
          count: int
        time\_bucket:
          period: \[hour | day | week | month]
          count: int
        detection\_delay:
          period: \[hour | day | week | month]
          count: int
        ignore\_small\_changes:
          spike\_failure\_percent\_threshold: int
          drop\_failure\_percent\_threshold: int
        anomaly\_exclude\_metrics: \[SQL expression]
```yml Models models: - name: < model name > tests: - elementary.freshness_anomalies: timestamp_column: < timestamp column > # Mandatory where_expression: < sql expression > time_bucket: # Daily by default period: < time period > count: < number of periods > ``` ```yml Models example models: - name: login_events tests: - elementary.freshness_anomalies: timestamp_column: "updated_at" # optional - use tags to run elementary tests on a dedicated run tags: ["elementary"] config: # optional - change severity severity: warn ```