diff --git a/docs/pages/product/data-modeling/concepts/calendar-cubes.mdx b/docs/pages/product/data-modeling/concepts/calendar-cubes.mdx
index 55fcf42a3b2b3..c95d6f1215d1c 100644
--- a/docs/pages/product/data-modeling/concepts/calendar-cubes.mdx
+++ b/docs/pages/product/data-modeling/concepts/calendar-cubes.mdx
@@ -110,6 +110,8 @@ cube('fiscal_calendar', {
 
 </CodeTabs>
 
+### Joins
+
 Calendar cubes are only useful when they are joined with other cubes in the data model.
 
 <CodeTabs>
@@ -144,6 +146,11 @@ cube(`sales`, {
 
 </CodeTabs>
 
+When joining a calendar cube to other cubes, the following requirements must be met:
+- The calendar cube's join dimension must be of [type `time`][ref-time-dimension] and
+also be the [`primary_key`][ref-primary-key].
+- The other cube's join dimension must also be of [type `time`][ref-time-dimension].
+
 ## Overriding time shifts
 
 Calendar cubes can be used to override the default time shift behavior of [time-shift
@@ -464,4 +471,6 @@ expression in the generated SQL.
 [ref-time-dimension]: /product/data-modeling/concepts#time-dimensions
 [ref-granularities]: /product/data-modeling/reference/dimensions#granularities
 [ref-cubes]: /product/data-modeling/reference/cube
-[ref-cubes-calendar]: /product/data-modeling/reference/cube#calendar
\ No newline at end of file
+[ref-cubes-calendar]: /product/data-modeling/reference/cube#calendar
+[link-tesseract]: https://cube.dev/blog/introducing-next-generation-data-modeling-engine
+[ref-primary-key]: /product/data-modeling/reference/dimensions#primary_key
\ No newline at end of file