Refactor reports to share definitions across intervals

README.md

@@ -27,18 +27,21 @@ Reports are written under the `output/` directory. Each command updates the corr
 ### Configuring Reports
 
 Report queries are defined in `reports.yml`. Each entry specifies the `name`,
-`interval`, optional `label` and `chart` type, and a SQL `query` that must return
-`bucket` and `value` columns. When `generate_reports.py` runs, every matching
-definition creates `output/<interval>/<name>.json` and an interval dashboard.
+optional `label` and `chart` type, and a SQL `query` that must return `bucket`
+and `value` columns. The special token `{bucket}` is replaced with the
+appropriate SQLite `strftime` expression for each interval (hourly, daily,
+weekly or monthly) so that a single definition works across all durations.
+When `generate_reports.py` runs, every definition is executed for the requested
+interval and creates `output/<interval>/<name>.json` along with an HTML
+dashboard.
 
 Example snippet:
 
 ```yaml
 - name: hits
-  interval: hourly
   chart: bar
   query: |
-    SELECT strftime('%Y-%m-%d %H:00:00', datetime(time)) AS bucket,
+    SELECT {bucket} AS bucket,
            COUNT(*) AS value
     FROM logs
     GROUP BY bucket