import time
import ntptime
import machine

def setup_rtc(tz_offset):
    ntptime.settime()
    rtc = machine.RTC()

    utc = time.localtime()
    local = time.localtime(time.mktime(utc) + tz_offset * 3600)

    rtc.datetime((
        local[0], local[1], local[2], 0,
        local[3], local[4], local[5], 0
    ))
    return rtc

# Function to calculate the difference
def calculate_difference(dt1, dt2):
    timestamp1 = rtc_to_timestamp(dt1)
    timestamp2 = rtc_to_timestamp(dt2)   
    difference = abs(timestamp2 - timestamp1)    
    days = difference // (24 * 3600)
    difference %= (24 * 3600)
    hours = difference // 3600
    difference %= 3600
    minutes = difference // 60
    seconds = difference % 60
    return days, hours, minutes, seconds

# Function to convert RTC datetime tuple to a timestamp
def rtc_to_timestamp(dt):
    year, month, day, weekday, hour, minute, second, subseconds = dt
    return time.mktime((year, month, day, hour, minute, second, 0, 0))