Fixes: Get minutes offset from start of the day over days.utc() (#1488)

* Use days start of the day offset minutes over days.utc()

* We do not need to set startOf("day") as day.utc() already starts from the beginning of the day with respective +h value

* do not use startOf if the invite date is already set with utc value, otherwise, it will double the utc +h * 2

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

lib/slots.ts

@@ -17,11 +17,11 @@ export type GetSlots = {
   minimumBookingNotice: number;
 };
 
-const getMinuteOffset = (date: Dayjs, step: number) => {
+const getMinuteOffset = (date: Dayjs, frequency: number) => {
   // Diffs the current time with the given date and iff same day; (handled by 1440) - return difference; otherwise 0
-  const minuteOffset = Math.min(date.diff(dayjs.utc().startOf("day"), "minute"), 1440) % 1440;
+  const minuteOffset = Math.min(date.diff(dayjs().utc(), "minute"), 1440) % 1440;
   // round down to nearest step
-  return Math.ceil(minuteOffset / step) * step;
+  return Math.ceil(minuteOffset / frequency) * frequency;
 };
 
 // eslint-disable-next-line @typescript-eslint/no-unused-vars

test/lib/slots.test.ts

@@ -16,7 +16,7 @@ it("can fit 24 hourly slots for an empty day", async () => {
   // 24h in a day.
   expect(
     getSlots({
-      inviteeDate: dayjs.utc().add(1, "day").startOf("day"),
+      inviteeDate: dayjs.utc().add(1, "day"),
       frequency: 60,
       minimumBookingNotice: 0,
       workingHours: [