From 0871314d5304024b48094a866dc1ffaefbd2a3c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Efra=C3=ADn=20Roch=C3=ADn?= <roae.85@gmail.com>
Date: Mon, 13 Mar 2023 02:59:19 -0700
Subject: [PATCH] Amend logic to figure out if selected slot is available
 (#7684)

---
 .../features/bookings/lib/handleNewBooking.ts | 27 ++++---------------
 packages/lib/slots.ts                         | 10 ++-----
 2 files changed, 7 insertions(+), 30 deletions(-)

diff --git a/packages/features/bookings/lib/handleNewBooking.ts b/packages/features/bookings/lib/handleNewBooking.ts
index bd6a977303..477322d04b 100644
--- a/packages/features/bookings/lib/handleNewBooking.ts
+++ b/packages/features/bookings/lib/handleNewBooking.ts
@@ -113,36 +113,20 @@ const isWithinAvailableHours = (
   {
     workingHours,
     organizerTimeZone,
-    inviteeTimeZone,
   }: {
     workingHours: WorkingHours[];
     organizerTimeZone: string;
-    inviteeTimeZone: string;
   }
 ) => {
   const timeSlotStart = dayjs(timeSlot.start).utc();
   const timeSlotEnd = dayjs(timeSlot.end).utc();
-  const isOrganizerInDST = isInDST(dayjs().tz(organizerTimeZone));
-  const isInviteeInDST = isInDST(dayjs().tz(inviteeTimeZone));
   const isOrganizerInDSTWhenSlotStart = isInDST(timeSlotStart.tz(organizerTimeZone));
-  const isInviteeInDSTWhenSlotStart = isInDST(timeSlotStart.tz(inviteeTimeZone));
   const organizerDSTDifference = getDSTDifference(organizerTimeZone);
-  const inviteeDSTDifference = getDSTDifference(inviteeTimeZone);
-  const sameDSTUsers = isOrganizerInDSTWhenSlotStart === isInviteeInDSTWhenSlotStart;
-  const organizerDST = isOrganizerInDST === isOrganizerInDSTWhenSlotStart;
-  const inviteeDST = isInviteeInDST === isInviteeInDSTWhenSlotStart;
-  const getTime = (slotTime: Dayjs, minutes: number) =>
-    slotTime
-      .startOf("day")
-      .add(
-        sameDSTUsers && organizerDST && inviteeDST
-          ? minutes
-          : minutes -
-              (isOrganizerInDSTWhenSlotStart || isOrganizerInDST
-                ? organizerDSTDifference
-                : inviteeDSTDifference),
-        "minutes"
-      );
+
+  const getTime = (slotTime: Dayjs, minutes: number) => {
+    const minutesDTS = isOrganizerInDSTWhenSlotStart ? minutes - organizerDSTDifference : minutes;
+    return slotTime.startOf("day").add(minutesDTS, "minutes");
+  };
   for (const workingHour of workingHours) {
     const startTime = getTime(timeSlotStart, workingHour.startTime);
     const endTime = getTime(timeSlotEnd, workingHour.endTime);
@@ -298,7 +282,6 @@ async function ensureAvailableUsers(
         {
           workingHours,
           organizerTimeZone: eventType.timeZone || eventType?.schedule?.timeZone || user.timeZone,
-          inviteeTimeZone: input.timeZone,
         }
       )
     ) {
diff --git a/packages/lib/slots.ts b/packages/lib/slots.ts
index e34c8b2413..57cf50112b 100644
--- a/packages/lib/slots.ts
+++ b/packages/lib/slots.ts
@@ -111,7 +111,6 @@ function buildSlots({
 
     return startOfInviteeDay.tz(inviteeTimeZone).add(minutes, "minutes");
   };
-
   for (const item of Object.values(slotsTimeFrameAvailable)) {
     /*
      * @calcom/web:dev: 2022-11-06T00:00:00-04:00
@@ -121,15 +120,10 @@ function buildSlots({
      * @calcom/web:dev: 2022-11-06T03:00:00-04:00
      * ...
      */
-    const slot = {
+    slots.push({
       userIds: item.userIds,
       time: getTime(item.startTime),
-    };
-    // If the startOfInviteeDay has a different UTC offset than the slot, a DST change has occurred.
-    // As the time has now fallen backwards, or forwards; this difference -
-    // needs to be manually added as this is not done for us. Usually 0.
-    slot.time = slot.time.add(startOfInviteeDay.utcOffset() - slot.time.utcOffset(), "minutes");
-    slots.push(slot);
+    });
   }
   return slots;
 }