diff --git a/server/src/routes/timeslot.ts b/server/src/routes/timeslot.ts
index b853481..a9df470 100644
--- a/server/src/routes/timeslot.ts
+++ b/server/src/routes/timeslot.ts
@@ -10,8 +10,8 @@ import Trainer from "../interfaces/trainer";
 import { ReservedTimeslots, Timeslot, WeeklyTimeslot } from "../interfaces/timeslot";
 import { idSchema, timeSchema } from "../schemas";
 
-dayjs.extend(isoWeek)
-dayjs.extend(utc)
+dayjs.extend(isoWeek);
+dayjs.extend(utc);
 
 const router: Router = express.Router();
 
@@ -29,8 +29,8 @@ const timeslotFiltersSchema = Joi.object({
 interface TimeslotFilters {
     trainer?: number[]
     center?: number
-    startDate: Date
-    endDate: Date
+    startDate: string
+    endDate: string
     startTime?: string
     endTime?: string
 }
@@ -85,8 +85,8 @@ router.get("/timeslot", async (req: Request, res: Response) => {
                         'end_time', end_time
                     )) FROM public.reserved_timeslots
                     WHERE 
-                        (start_time between '2023-04-16' AND '2023-04-20'
-                        OR end_time between '2023-04-16' AND '2023-04-20')
+                        (start_time between $1 AND $2
+                        OR end_time between $1 AND $2)
                         AND weekly_timeslots.trainer_id = reserved_timeslots.trainer_id
                 ) as reserved_timeslots
             FROM
@@ -95,9 +95,9 @@ router.get("/timeslot", async (req: Request, res: Response) => {
             JOIN users ON trainers.user_id = users.id
             JOIN centers ON trainers.center_id = centers.id
             WHERE
-                ((trainer_id = ANY($1)) OR $2)
-                AND (day_of_week = ANY($3))
-                AND (trainers.center_id = $4 OR $5)
+                ((trainer_id = ANY($3)) OR $4)
+                AND (day_of_week = ANY($5))
+                AND (trainers.center_id = $6 OR $7)
             GROUP BY
                 weekly_timeslots.trainer_id,
                 users.first_name,
@@ -106,6 +106,8 @@ router.get("/timeslot", async (req: Request, res: Response) => {
                 centers.name,
                 trainer_id;
         `, [
+            new Date(timeslotFilters.startDate).toISOString(),
+            new Date(timeslotFilters.endDate).toISOString(),
             timeslotFilters.trainer !== undefined ? timeslotFilters.trainer : [1],
             timeslotFilters.trainer === undefined,
             weekdays,
@@ -125,7 +127,7 @@ router.get("/timeslot", async (req: Request, res: Response) => {
 
             for (let day: dayjs.Dayjs = filterStartDate; !day.isAfter(filterEndDate); day = day.add(1, "day")) {
                 const weekDay = day.isoWeekday();
-                const reservedTimeslots = trainer.reserved_timeslots;
+                const reservedTimeslots = trainer.reserved_timeslots !== null ? trainer.reserved_timeslots : [];
 
                 timeslots: for (const timeslot of trainer.timeslots) {
                     if (timeslot.day_of_week !== weekDay)