diff --git a/application/Espo/ORM/Query/Part/Expression.php b/application/Espo/ORM/Query/Part/Expression.php
index e2e3c46aec..564a176bbb 100644
--- a/application/Espo/ORM/Query/Part/Expression.php
+++ b/application/Espo/ORM/Query/Part/Expression.php
@@ -539,6 +539,46 @@ class Expression implements WhereItem
         return self::composeFunction('UNIX_TIMESTAMP', $dateTime);
     }
 
+    /**
+     * Difference between two dates in days. Floor is applied.
+     *
+     * @since 10.0.0
+     */
+    public function timestampDiffDay(Expression $from, Expression $to): self
+    {
+        return self::composeFunction('TIMESTAMPDIFF_DAY', $from, $to);
+    }
+
+    /**
+     * Difference between two dates in hours. Floor is applied.
+     *
+     * @since 10.0.0
+     */
+    public function timestampDiffHour(Expression $from, Expression $to): self
+    {
+        return self::composeFunction('TIMESTAMPDIFF_HOUR', $from, $to);
+    }
+
+    /**
+     * Difference between two dates in minutes. Floor is applied.
+     *
+     * @since 10.0.0
+     */
+    public function timestampDiffMinute(Expression $from, Expression $to): self
+    {
+        return self::composeFunction('TIMESTAMPDIFF_MINUTE', $from, $to);
+    }
+
+    /**
+     * Difference between two dates in seconds.
+     *
+     * @since 10.0.0
+     */
+    public function timestampDiffSecond(Expression $from, Expression $to): self
+    {
+        return self::composeFunction('TIMESTAMPDIFF_SECOND', $from, $to);
+    }
+
     /**
      * 'NOW' function. A current date and time.
      */
diff --git a/application/Espo/ORM/QueryComposer/PostgresqlQueryComposer.php b/application/Espo/ORM/QueryComposer/PostgresqlQueryComposer.php
index f933efd3bb..a59f7bd952 100644
--- a/application/Espo/ORM/QueryComposer/PostgresqlQueryComposer.php
+++ b/application/Espo/ORM/QueryComposer/PostgresqlQueryComposer.php
@@ -346,10 +346,10 @@ class PostgresqlQueryComposer extends BaseQueryComposer
                     return "FLOOR(($toEpoch - $fromEpoch) / (3600 * 24))";
 
                 case 'TIMESTAMPDIFF_HOUR':
-                    return "($toEpoch - $fromEpoch) / 3600";
+                    return "FLOOR(($toEpoch - $fromEpoch) / 3600)";
 
                 case 'TIMESTAMPDIFF_MINUTE':
-                    return "($toEpoch - $fromEpoch) / 60";
+                    return "FLOOR(($toEpoch - $fromEpoch) / 60)";
 
                 case 'TIMESTAMPDIFF_SECOND':
                     return "$toEpoch - $fromEpoch";