playground.swift

import Foundation

// https://twitter.com/peres/status/1353810351264034818

func daysBetweenDates(start: Date, end: Date, calendar: Calendar) -> [Date] {
    guard let diff = cal.dateComponents([.day], from: start, to: end).day else {
        return []
    }
    // if you need to include end in the array, use 0...diff+1
    return (0...diff).compactMap {
        cal.date(byAdding: .day, value: $0, to: start)
    }
}

let cal = Calendar.autoupdatingCurrent
let today = Date()
let marchThird = cal.date(from: DateComponents(calendar: cal, year: 2021, month: 3, day: 3, hour: 12, minute: 0, second: 0))

daysBetweenDates(start: today, end: marchThird!, calendar: cal)