Add docs

Author: igorlukanin

docs/pages/reference/data-model/dimensions.mdx

@@ -618,6 +618,14 @@ examples.
 
 </ReferenceBox>
 
+<WarningBox>
+
+Custom granularities are supported for the following [data sources][ref-data-sources]:
+Amazon Athena, Amazon Redshift, DuckDB, Databricks, Google BigQuery, ClickHouse, Microsoft SQL Server, MySQL, Postgres, and Snowflake.
+Please [file an issue](https://github.com/cube-js/cube/issues) if you need support for another data source.
+
+</WarningBox>
+
 For each custom granularity, the `interval` parameter is required. It specifies
 the duration of the time interval and has the following format:
 `quantity unit [quantity unit...]`, e.g., `5 days` or `1 year 6 months`.
@@ -713,4 +721,5 @@ cube(`orders`, {
 [ref-time-dimensions]: /reference/data-model/types-and-formats#time-1
 [link-date-time-string]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_time_string_format
 [ref-custom-granularity-recipe]: /guides/recipes/data-modeling/custom-granularity
-[ref-ref-hierarchies]: /reference/data-model/hierarchies
+[ref-ref-hierarchies]: /reference/data-model/hierarchies
+[ref-data-sources]: /product/configuration/data-sources

packages/cubejs-schema-compiler/src/adapter/BaseQuery.js

@@ -3110,7 +3110,7 @@ export class BaseQuery {
    */
   // eslint-disable-next-line @typescript-eslint/no-unused-vars
   dateBin(interval, source, origin) {
-    throw new Error('Date bin function is not implemented');
+    throw new Error('Date bin function, required for custom time dimension granularities, is not implemented for this data source');
     // Different syntax possible in different DBs
   }