1 files changed, 3 insertions, 0 deletions
diff --git a/src/include/pgtime.h b/src/include/pgtime.h
index 2977b13aabb..441d7847c12 100644
--- a/src/include/pgtime.h
+++ b/src/include/pgtime.h
@@ -23,6 +23,8 @@
 typedef int64 pg_time_t;
 
 /*
+ * Data structure representing a broken-down timestamp.
+ *
  * CAUTION: the IANA timezone library (src/timezone/) follows the POSIX
  * convention that tm_mon counts from 0 and tm_year is relative to 1900.
  * However, Postgres' datetime functions generally treat tm_mon as counting
@@ -44,6 +46,7 @@ struct pg_tm
 	const char *tm_zone;
 };
 
+/* These structs are opaque outside the timezone library */
 typedef struct pg_tz pg_tz;
 typedef struct pg_tzenum pg_tzenum;