diff --git a/libpretixsync/src/main/java/eu/pretix/libpretixsync/api/PretixApi.kt b/libpretixsync/src/main/java/eu/pretix/libpretixsync/api/PretixApi.kt
index de7b221f..66715694 100644
--- a/libpretixsync/src/main/java/eu/pretix/libpretixsync/api/PretixApi.kt
+++ b/libpretixsync/src/main/java/eu/pretix/libpretixsync/api/PretixApi.kt
@@ -3,9 +3,9 @@ package eu.pretix.libpretixsync.api
 import eu.pretix.libpretixsync.DummySentryImplementation
 import eu.pretix.libpretixsync.SentryInterface
 import eu.pretix.libpretixsync.config.ConfigStore
-import eu.pretix.libpretixsync.db.AbstractQueuedCheckIn
 import eu.pretix.libpretixsync.db.Answer
 import eu.pretix.libpretixsync.models.Question
+import eu.pretix.libpretixsync.models.QueuedCheckIn
 import eu.pretix.libpretixsync.utils.NetUtils
 import eu.pretix.libpretixsync.utils.URLFragmentEncoder
 import okhttp3.MediaType
@@ -46,7 +46,7 @@ open class PretixApi(url: String, key: String, orgaSlug: String, version: Int, h
     fun redeem(eventSlug: String, secret: String, datetime: Date?, force: Boolean, nonce: String?, answers: List<Answer>?, listId: Long, ignore_unpaid: Boolean, pdf_data: Boolean, type: String?, source_type: String?, callTimeout: Long? = null, questions_supported: Boolean = true): ApiResponse {
         var dt: String? = null
         if (datetime != null) {
-            dt = AbstractQueuedCheckIn.formatDatetime(datetime)
+            dt = QueuedCheckIn.formatDatetime(datetime)
         }
         return redeem(eventSlug, secret, dt, force, nonce, answers, listId, ignore_unpaid, pdf_data, type, source_type, callTimeout, questions_supported)
     }
@@ -93,7 +93,7 @@ open class PretixApi(url: String, key: String, orgaSlug: String, version: Int, h
     fun redeem(lists: List<Long>, secret: String, datetime: Date?, force: Boolean, nonce: String?, answers: List<Answer>?, ignore_unpaid: Boolean, pdf_data: Boolean, type: String?, source_type: String?, callTimeout: Long? = null, questions_supported: Boolean = true): ApiResponse {
         var dt: String? = null
         if (datetime != null) {
-            dt = AbstractQueuedCheckIn.formatDatetime(datetime)
+            dt = QueuedCheckIn.formatDatetime(datetime)
         }
         return redeem(lists, secret, dt, force, nonce, answers, ignore_unpaid, pdf_data, type, source_type, callTimeout, questions_supported)
     }
diff --git a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/AsyncCheckProvider.kt b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/AsyncCheckProvider.kt
index a2dc317d..3c02b637 100644
--- a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/AsyncCheckProvider.kt
+++ b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/AsyncCheckProvider.kt
@@ -7,7 +7,6 @@ import eu.pretix.libpretixsync.config.ConfigStore
 import eu.pretix.libpretixsync.crypto.isValidSignature
 import eu.pretix.libpretixsync.crypto.readPubkeyFromPem
 import eu.pretix.libpretixsync.crypto.sig1.TicketProtos
-import eu.pretix.libpretixsync.db.AbstractQueuedCheckIn
 import eu.pretix.libpretixsync.db.Answer
 import eu.pretix.libpretixsync.db.NonceGenerator
 import eu.pretix.libpretixsync.db.QuestionLike
@@ -66,7 +65,7 @@ class AsyncCheckProvider(private val config: ConfigStore, private val db: SyncDa
 
         val dt = now()
         val jdoc = JSONObject()
-        jdoc.put("datetime", AbstractQueuedCheckIn.formatDatetime(dt.toDate()))
+        jdoc.put("datetime", QueuedCheckIn.formatDatetime(dt.toDate()))
         if (raw_barcode.contains(Regex("[\\p{C}]"))) {
             jdoc.put("raw_barcode", "binary:" + Base64.encodeBase64(raw_barcode.toByteArray(Charset.defaultCharset())).toString(Charset.defaultCharset()))
         } else {
@@ -521,7 +520,7 @@ class AsyncCheckProvider(private val config: ConfigStore, private val db: SyncDa
                     answers = givenAnswers.toString(),
                     checkinListId = listId,
                     datetime = dt.toDate(),
-                    datetime_string = AbstractQueuedCheckIn.formatDatetime(dt.toDate()),
+                    datetime_string = QueuedCheckIn.formatDatetime(dt.toDate()),
                     event_slug = eventSlug,
                     nonce = nonce ?: NonceGenerator.nextNonce(),
                     secret = ticketid,
@@ -929,7 +928,7 @@ class AsyncCheckProvider(private val config: ConfigStore, private val db: SyncDa
                     answers = givenAnswers.toString(),
                     checkinListId = listId,
                     datetime = dt.toDate(),
-                    datetime_string = AbstractQueuedCheckIn.formatDatetime(dt.toDate()),
+                    datetime_string = QueuedCheckIn.formatDatetime(dt.toDate()),
                     event_slug = eventSlug,
                     nonce = nonce ?: NonceGenerator.nextNonce(),
                     secret = position.secret,
@@ -943,7 +942,7 @@ class AsyncCheckProvider(private val config: ConfigStore, private val db: SyncDa
                     position = position.id,
                     type = type.toString().lowercase(Locale.getDefault()),
                     datetime = dt.toDate(),
-                    json_data = "{\"local\": true, \"type\": \"${type.toString().lowercase(Locale.getDefault())}\", \"datetime\": \"${AbstractQueuedCheckIn.formatDatetime(dt.toDate())}\"}",
+                    json_data = "{\"local\": true, \"type\": \"${type.toString().lowercase(Locale.getDefault())}\", \"datetime\": \"${QueuedCheckIn.formatDatetime(dt.toDate())}\"}",
                 )
             }
         }
diff --git a/libpretixsync/src/main/java/eu/pretix/libpretixsync/models/QueuedCheckIn.kt b/libpretixsync/src/main/java/eu/pretix/libpretixsync/models/QueuedCheckIn.kt
index 6e23f145..b451ef68 100644
--- a/libpretixsync/src/main/java/eu/pretix/libpretixsync/models/QueuedCheckIn.kt
+++ b/libpretixsync/src/main/java/eu/pretix/libpretixsync/models/QueuedCheckIn.kt
@@ -1,6 +1,11 @@
 package eu.pretix.libpretixsync.models
 
+import java.text.DateFormat
+import java.text.SimpleDateFormat
 import java.time.OffsetDateTime
+import java.util.Date
+import java.util.Locale
+import java.util.TimeZone
 
 data class QueuedCheckIn(
     val id: Long,
@@ -12,4 +17,18 @@ data class QueuedCheckIn(
     val secret: String?,
     val sourceType: String?,
     val type: String?,
-)
+) {
+    companion object {
+        // Migrated from AbstractQueuedCheckIn
+        // TODO: Find a better place for this?
+        fun formatDatetime(date: Date): String {
+            val tz = TimeZone.getTimeZone("UTC")
+            val df: DateFormat = SimpleDateFormat(
+                "yyyy-MM-dd'T'HH:mm:ss'Z'",
+                Locale.ENGLISH
+            ) // Quoted "Z" to indicate UTC, no timezone offset
+            df.timeZone = tz
+            return df.format(date)
+        }
+    }
+}