Time Metrics

Use `default_date` and `canon_date` so Zoë trends each metric against the correct time dimension.

Each metric in Zenlytic should be associated with a time dimension group. The associated dimension group with a metric is called that metric's canon_date.

⏱️ This let's Zoë apply time periods correctly and trend metrics over time while guaranteeing that we're using the right time dimension.

You can associate a time dimension with a view using the default_date property.

version: 1
type: view
name: google_ad_stats
model_name: my_company 
sql_table_name: PROD.GOOGLE_AD_STATS
default_date: ad_stat_recorded_at

fields:
- name: ad_stat_recorded_at
  field_type: dimension_group
  type: time
  datatype: date
  timeframes:
  - raw
  - date
  - week
  - month
  - quarter
  - year
  sql: ${TABLE}.DATE

Under the default date property you'll just reference the name of the time you want to use as the default date.

The default date will be the default canon_date for all metrics in that view unless their canon_date is set on the metric explicitly.

🛠 You can also use a canon_date or default_date that is not in the same table as your metric. To use that date, just make sure it is possible to join that field in, and reference it like default_date: google_record_stats.recorded_at, using the view name before the field name.

Using an example from subscription management:

version: 1
type: view
name: subscriptions
model_name: my_company
sql_table_name: PROD.SUBSCRIPTIONS
default_date: created_at

fields:
- name: created_at
  field_type: dimension_group
  type: time
  timeframes:
  - raw
  - date
  - week
  - month
  - quarter
  - year
  sql: ${TABLE}.CREATED_AT

- name: canceled_at
  field_type: dimension_group
  type: time
  timeframes:
  - raw
  - date
  - week
  - month
  - quarter
  - year
  sql: ${TABLE}.CANCELED_AT

- name: new_subscriptions
  field_type: measure
  type: count_distinct
  sql: ${subscription_id}
  description: "This is the unique number of subscriptions by the date created"

- name: canceled_subscriptions
  field_type: measure
  type: count_distinct
  sql: ${subscription_id}
  canon_date: canceled_at
  description: "This is the unique number of subscriptions by the date canceled"

The first measure inherits the canon_date of created_at from the default_date on the view, and the second one is set explicitly to be canceled_at because its definition needs to use another date to derive its meaning.