Fix Up/Down month shortcuts

Author: probablykasper

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Next
 - Fix broken month dropdown on Firefox
 - Fix unreliable clamping to min/max dates
+- Fix month `Up/Down` arrow key shortcuts
 
 ## 2.1.0 - 2022 Jul 31
 - Add `browseWithoutSelecting` property

src/lib/DatePicker.svelte

@@ -171,9 +171,9 @@
       shiftKeydown(e)
       return
     } else if (e.key === 'ArrowUp') {
-      setMonth(browseDate.getFullYear() - 1)
+      setMonth(browseDate.getMonth() - 1)
     } else if (e.key === 'ArrowDown') {
-      setMonth(browseDate.getFullYear() + 1)
+      setMonth(browseDate.getMonth() + 1)
     } else if (e.key === 'ArrowLeft') {
       setMonth(browseDate.getFullYear() - 1)
     } else if (e.key === 'ArrowRight') {