diff --git a/src/main/kotlin/com/restapi/config/Auth.kt b/src/main/kotlin/com/restapi/config/Auth.kt
index 8fc6584..94f145d 100644
--- a/src/main/kotlin/com/restapi/config/Auth.kt
+++ b/src/main/kotlin/com/restapi/config/Auth.kt
@@ -28,6 +28,7 @@ import java.net.http.HttpResponse
 import java.nio.charset.StandardCharsets
 import java.time.LocalDateTime
 import java.time.ZoneId
+import java.time.format.DateTimeFormatter
 import java.util.*
 import java.util.concurrent.ConcurrentHashMap
 
@@ -275,10 +276,10 @@ object Auth {
             foundOldAt.refreshHistory = (foundOldAt.refreshHistory ?: arrayListOf()).apply {
                 add(RefreshHistory(
                     oldAt = authUser.token,
-                    oldExpiryAt = expiresAt,
+                    oldExpiryAt = expiresAt.format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
                     newAt = atResponse.accessToken,
-                    newExpiryAt = LocalDateTime.now().plusSeconds(atResponse.expiresIn.toLong()),
-                    createdAt = LocalDateTime.now()
+                    newExpiryAt = LocalDateTime.now().plusSeconds(atResponse.expiresIn.toLong()).format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
+                    createdAt = LocalDateTime.now().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME),
                 ))
             }
             database.update(foundOldAt)
diff --git a/src/main/kotlin/com/restapi/domain/models.kt b/src/main/kotlin/com/restapi/domain/models.kt
index 37c212a..f4d9af0 100644
--- a/src/main/kotlin/com/restapi/domain/models.kt
+++ b/src/main/kotlin/com/restapi/domain/models.kt
@@ -690,10 +690,10 @@ open class Plant : BaseModel() {
 
 data class RefreshHistory(
     val oldAt: String,
-    val oldExpiryAt: LocalDateTime,
+    val oldExpiryAt: String,
     val newAt: String,
-    val newExpiryAt: LocalDateTime,
-    val createdAt: LocalDateTime
+    val newExpiryAt: String,
+    val createdAt: String
 )
 @Entity
 open class AuthTokenCache : BaseModel() {