diff --git a/src/lib/import/airtrail.ts b/src/lib/import/airtrail.ts
index 160c19e..3704efe 100644
--- a/src/lib/import/airtrail.ts
+++ b/src/lib/import/airtrail.ts
@@ -36,7 +36,7 @@ const AirTrailFile = z.object({
         .string()
         .min(3, { message: 'Username must be at least 3 characters long' })
         .max(20, { message: 'Username must be at most 20 characters long' })
-        .regex(/^[a-zA-Z0-9_]+$/, {
+        .regex(/^\w+$/, {
           message:
             'Username can only contain letters, numbers, and underscores',
         }),
diff --git a/src/lib/import/aita.ts b/src/lib/import/aita.ts
index f049f28..2febb24 100644
--- a/src/lib/import/aita.ts
+++ b/src/lib/import/aita.ts
@@ -18,7 +18,7 @@ const AITA_SEAT_CLASS_MAP: Record<string, (typeof SeatClasses)[number]> = {
 
 export const processAITAFile = (input: string, options: PlatformOptions) => {
   const tripPattern =
-    /^Ownership\.([\w]+);[^\r\n]*\sflights:\s([\s\S]+?)\shotels:/gm;
+    /^Ownership\.(\w+);[^\r\n]*\sflights:\s([\s\S]+?)\shotels:/gm;
   const flightPattern =
     /^([^;\n\r]*);(\w*);.*?;(\w{2,4};\d{2,4});(\w*);(\w{3});(\w{3});([\d\-T:]+);([\d\-T:]+);([\d\-T:]+);([\d\-T:]+);(.*)/gm;
 
diff --git a/src/lib/import/jetlog.ts b/src/lib/import/jetlog.ts
index 4b01529..6f20fa4 100644
--- a/src/lib/import/jetlog.ts
+++ b/src/lib/import/jetlog.ts
@@ -19,23 +19,27 @@ const JETLOG_FLIGHT_CLASS_MAP: Record<string, Seat['seatClass']> = {
 };
 
 const nullTransformer = (v: string) => (v === '' ? null : v);
+const dateRegex = /^\d{4}-\d{2}-\d{2}$/;
+const optionalTimePrimitive = z
+  .string()
+  .refine((v) => v === '' || v.match(/^\d{2}:\d{2}$/), {
+    message: 'Invalid time format',
+  })
+  .transform(nullTransformer);
+const optionalDatePrimitive = z
+  .string()
+  .refine((v) => v === '' || v.match(dateRegex), {
+    message: 'Invalid date format',
+  })
+  .transform(nullTransformer);
 
 const JetLogFlight = z.object({
-  date: z.string().regex(/^\d{4}-\d{2}-\d{2}$/),
+  date: z.string().regex(dateRegex),
   origin: z.string(),
   destination: z.string(),
-  departure_time: z
-    .string()
-    .regex(/^\d{2}:\d{2}$|/)
-    .transform(nullTransformer),
-  arrival_time: z
-    .string()
-    .regex(/^\d{2}:\d{2}$|/)
-    .transform(nullTransformer),
-  arrival_date: z
-    .string()
-    .regex(/^\d{4}-\d{2}-\d{2}$|/)
-    .transform(nullTransformer),
+  departure_time: optionalTimePrimitive,
+  arrival_time: optionalTimePrimitive,
+  arrival_date: optionalDatePrimitive,
   seat: z.enum(['window', 'middle', 'aisle', '']).transform(nullTransformer),
   ticket_class: z.string().transform(nullTransformer),
   duration: z.string().transform(nullTransformer),
diff --git a/src/lib/server/utils/oauth.ts b/src/lib/server/utils/oauth.ts
index 228a9ea..fdd5e73 100644
--- a/src/lib/server/utils/oauth.ts
+++ b/src/lib/server/utils/oauth.ts
@@ -54,7 +54,7 @@ export const getOAuthClient = async () => {
 
   const { enabled, clientId, clientSecret, issuerUrl } = config.oauth;
   if (!enabled || !clientId || !clientSecret || !issuerUrl) {
-    throw new Error('OAuth is not enabled');
+    throw new Error('OAuth is not enabled or configured properly');
   }
 
   try {
diff --git a/src/lib/utils/data/data.ts b/src/lib/utils/data/data.ts
index a0ca2b6..a07d2ec 100644
--- a/src/lib/utils/data/data.ts
+++ b/src/lib/utils/data/data.ts
@@ -217,15 +217,20 @@ export const formatSeat = (f: FlightData) => {
   const s = f.seats.find((seat) => seat.userId === userId);
   if (!s) return null;
 
-  return s.seat && s.seatNumber && s.seatClass
-    ? `${t(s.seatClass)} (${s.seat} ${s.seatNumber})`
-    : s.seat && s.seatNumber
-      ? `${s.seat} ${s.seatNumber}`
-      : s.seat && s.seatClass
-        ? `${t(s.seatClass)} (${s.seat})`
-        : s.seatClass
-          ? t(s.seatClass)
-          : s.seat
-            ? t(s.seat)
-            : null;
+  if (s.seat && s.seatNumber && s.seatClass) {
+    return `${t(s.seatClass)} (${s.seat} ${s.seatNumber})`;
+  }
+  if (s.seat && s.seatNumber) {
+    return `${s.seat} ${s.seatNumber}`;
+  }
+  if (s.seat && s.seatClass) {
+    return `${t(s.seatClass)} (${s.seat})`;
+  }
+  if (s.seatClass) {
+    return t(s.seatClass);
+  }
+  if (s.seat) {
+    return t(s.seat);
+  }
+  return null;
 };
diff --git a/src/lib/zod/flight.ts b/src/lib/zod/flight.ts
index ae3d267..70f5f8d 100644
--- a/src/lib/zod/flight.ts
+++ b/src/lib/zod/flight.ts
@@ -2,11 +2,25 @@ import { z } from 'zod';
 
 import { FlightReasons, SeatClasses, SeatTypes } from '$lib/db/types';
 
-// |^$ is for empty string in the case where the user deletes the input
-const regex24h =
-  /^([01]?[0-9]|2[0-3])(?::|\.|)[0-5][0-9](?:\s?(?:am|pm))?$|^$/i;
+const regex24h = /^([01]?\d|2[0-3])(?::|\.|)[0-5]\d(?:\s?(?:am|pm))?$/i;
 const regex12hLike = /^\d{1,2}(?::|\.|)\d{2}\s?(?:am|pm)$/i;
-const regex12h = /^([1-9]|1[0-2])(?::|\.|)[0-5][0-9]\s?(?:am|pm)$/i;
+const regex12h = /^([1-9]|1[0-2])(?::|\.|)[0-5]\d\s?(?:am|pm)$/i;
+
+const timePrimitive = z
+  .string()
+  .refine((value) => {
+    // Always allow empty string (to allow the user to delete the input)
+    if (value === '') return true;
+
+    return regex24h.test(value);
+  }, 'Invalid 24-hour format')
+  .refine((value) => {
+    // Skip 12-hour check if empty or not possibly 12-hour format (caught by the previous refine)
+    if (value === '' || !regex12hLike.test(value)) return true;
+
+    return regex12h.test(value);
+  }, 'Invalid 12-hour format')
+  .nullable();
 
 export const flightAirportsSchema = z.object({
   from: z.string().min(1, 'Select an origin'),
@@ -19,30 +33,12 @@ export const flightDateTimeSchema = z.object({
     .datetime({ offset: true, message: 'Select a departure date' })
     .nullable()
     .refine((value) => value !== null, 'Select a departure date'),
-  departureTime: z
-    .string()
-    .refine((value) => regex24h.test(value), 'Invalid 24-hour format')
-    .refine((value) => {
-      if (regex12hLike.test(value)) {
-        return regex12h.test(value);
-      }
-      return true; // If it's not in 12-hour format, just return true (it'll be caught by the previous refine)
-    }, 'Invalid 12-hour format')
-    .nullable(),
+  departureTime: timePrimitive,
   arrival: z
     .string()
     .datetime({ offset: true, message: 'Select an arrival date' })
     .nullable(),
-  arrivalTime: z
-    .string()
-    .refine((value) => regex24h.test(value), 'Invalid 24-hour format')
-    .refine((value) => {
-      if (regex12hLike.test(value)) {
-        return regex12h.test(value);
-      }
-      return true; // If it's not in 12-hour format, just return true (it'll be caught by the previous refine)
-    }, 'Invalid 12-hour format')
-    .nullable(),
+  arrivalTime: timePrimitive,
 });
 
 export const flightSeatInformationSchema = z.object({
diff --git a/src/lib/zod/user.ts b/src/lib/zod/user.ts
index 3178262..4ce146e 100644
--- a/src/lib/zod/user.ts
+++ b/src/lib/zod/user.ts
@@ -5,7 +5,7 @@ export const userSchema = z.object({
     .string()
     .min(3, { message: 'Username must be at least 3 characters long' })
     .max(20, { message: 'Username must be at most 20 characters long' })
-    .regex(/^[a-zA-Z0-9_]+$/, {
+    .regex(/^\w+$/, {
       message: 'Username can only contain letters, numbers, and underscores',
     }),
   password: z.string().min(8),
diff --git a/src/routes/api/flight/save/+server.ts b/src/routes/api/flight/save/+server.ts
index ee09656..d531839 100644
--- a/src/routes/api/flight/save/+server.ts
+++ b/src/routes/api/flight/save/+server.ts
@@ -1,11 +1,5 @@
 import type { TZDate } from '@date-fns/tz';
-import {
-  differenceInSeconds,
-  format,
-  formatISO,
-  isBefore,
-  isValid,
-} from 'date-fns';
+import { differenceInSeconds, format, formatISO, isBefore } from 'date-fns';
 import { actionResult, setError, superValidate } from 'sveltekit-superforms';
 import { zod } from 'sveltekit-superforms/adapters';