diff --git a/src/test/kotlin/pt/up/fe/ni/website/backend/utils/ValidationTester.kt b/src/test/kotlin/pt/up/fe/ni/website/backend/utils/ValidationTester.kt
index 170980cd..1ff0dc0e 100644
--- a/src/test/kotlin/pt/up/fe/ni/website/backend/utils/ValidationTester.kt
+++ b/src/test/kotlin/pt/up/fe/ni/website/backend/utils/ValidationTester.kt
@@ -1,6 +1,7 @@
 package pt.up.fe.ni.website.backend.utils
 
 import java.time.LocalDate
+import java.time.format.DateTimeFormatter
 import org.springframework.http.MediaType
 import org.springframework.test.web.servlet.ResultActions
 import org.springframework.test.web.servlet.result.MockMvcResultMatchers.content
@@ -114,8 +115,10 @@ class ValidationTester(
 
     fun isPastDate() {
         // get the current date and offset it by 1 day
+        val timeFormatter = DateTimeFormatter.ofPattern("dd-MM-yyyy")
         val tomorrow = LocalDate.now()
             .plusDays(1)
+            .format(timeFormatter)
             .toString()
 
         val params = requiredFields.toMutableMap()