Updated calendar picker

src/components/date-picker.tsx

@@ -10,7 +10,7 @@ import { Popover, PopoverContent, PopoverTrigger } from "@/components/ui/popover
 import { cn } from "@/lib/utils"
 
 interface DatePickerProps {
-    value?: Date
+    value?: Date | null
     onChange?: (date: Date | undefined) => void
 }
 
@@ -35,8 +35,9 @@ export function DatePicker({
             <PopoverContent className="w-auto p-0" align="start">
                 <Calendar
                     mode="single"
-                    selected={value}
+                    selected={value ?? undefined}
                     onSelect={onChange}
+                    weekStartsOn={1}
                 />
             </PopoverContent>
         </Popover>