timezone support in MicroPython ?

[andydatablocks]

def dstTime():
year = time.localtime()[0] #get current year
# print(year)
HHMarch = time.mktime((year,3 ,(14-(int(5*year/4+1))%7),1,0,0,0,0,0)) #Time of March change to DST
HHNovember = time.mktime((year,10,(7-(int(5*year/4+1))%7),1,0,0,0,0,0)) #Time of October change to EST
# print(HHNovember)
now=time.time()
if now < HHMarch : # we are before last sunday of march
dst=time.localtime(now-18000) # EST: UTC-5H
elif now < HHNovember : # we are before last sunday of october
dst=time.localtime(now-14400) # DST: UTC-4H
else: # we are after last sunday of october
dst=time.localtime(now-18000) # EST: UTC-5H
return(dst)

[kwtf]

Easiest way I found is changing ntptimes internal NTP_DELTA Variable, so it calculates it right.
Run ntptime.settime() after boardinit to have the correct time before execution.
Get tuple afterwards with utime.localtime()

Code: Select all

def getntptime(timer):
    year = utime.localtime()[0]       #get current year
    now=ntptime.time()
    HHMarch   = utime.mktime((year,3 ,(31-(int(5*year/4+4))%7),1,0,0,0,0,0)) #Time of March change to CEST
    HHOctober = utime.mktime((year,10,(31-(int(5*year/4+1))%7),1,0,0,0,0,0)) #Time of October change to CET
    if now < HHMarch :               # we are before last sunday of march
        ntptime.NTP_DELTA = 3155673600-3600 # CET:  UTC+1H
    elif now < HHOctober :           # we are before last sunday of october
        ntptime.NTP_DELTA = 3155673600-7200 # CEST: UTC+2H
    else:                            # we are after last sunday of october
        ntptime.NTP_DELTA = 3155673600-3600 # CET:  UTC+1H
    
    ntptime.settime() # set the rtc datetime from the remote server

[enzo]

Easiest way I found is changing ntptimes internal NTP_DELTA Variable, so it calculates it right.
Run ntptime.settime() after boardinit to have the correct time before execution.
Get tuple afterwards with utime.localtime()

Code: Select all

def getntptime(timer):
    year = utime.localtime()[0]       #get current year
    now=ntptime.time()
    HHMarch   = utime.mktime((year,3 ,(31-(int(5*year/4+4))%7),1,0,0,0,0,0)) #Time of March change to CEST
    HHOctober = utime.mktime((year,10,(31-(int(5*year/4+1))%7),1,0,0,0,0,0)) #Time of October change to CET
    if now < HHMarch :               # we are before last sunday of march
        ntptime.NTP_DELTA = 3155673600-3600 # CET:  UTC+1H
    elif now < HHOctober :           # we are before last sunday of october
        ntptime.NTP_DELTA = 3155673600-7200 # CEST: UTC+2H
    else:                            # we are after last sunday of october
        ntptime.NTP_DELTA = 3155673600-3600 # CET:  UTC+1H
    
    ntptime.settime() # set the rtc datetime from the remote server

Great workaround!
Please, can you tell why I get this error:
" File "ntptime.py", line 35, in settime
OverflowError: overflow converting long int to machine word"
When I run it on my ESP 8266 NODEMCU?
Thanks for your time!

[diggy]

Same error here.

Code: Select all

  File "ntptime.py", line 35, in settime
OverflowError: overflow converting long int to machine word

[pythoncoder]

What firmware are you guys using? I can't replicate this with firmware built today.

[davef]

kwtf,

Thanks for posting your solution.

Unfortunately, NZ change back to NZST on the first Sunday in April at 3AM, which left me wondering if:

Code: Select all

HHApril   = utime.mktime((year,4,(7-(int(5*year/4+4))%7),3,0,0,0,0,0))

would be correct. I couldn't find any Google hits on what appears to be a "magic" formula:

Code: Select all

31-(int(5*year/4+4))%7

Did find some information suggesting that Robert Harry van Gent was responsible for the CET forumlaes but searched all around his website without finding out how to calculate the mday number.

Can someone post a link to how to work this out?

Thanks.

[Stephen Betts]

the timzone had not bothered me with my projects until i made a neopixel clock and we switched to daylight savings recently.

So this is what I have come up with for my timezone calculations based on the input from the earlier posts by davef and enzo
The different months, March, April, September and October / first and last sunday all have a different offsets based so you will need to play around with those for your timezone. This has have been check against https://www.timeanddate.com/ for the NZ timezone up to 2030.

there is probably some additions that could be included but this met my needs for now

https://en.wikipedia.org/wiki/List_of_UTC_time_offsets
https://www.iana.org/time-zones

I basically run this code on boot, and once a day to keep the RTC in sync correctly

Code: Select all

# ###################################################################### #
# Set RTC localTime from UTC and apply DST offset
# Requires import machine, utime, ntptime
# assumes active network, otherwise will raise error whch is not currently dealt with
# Note: dstOffset should be between -12 and +14 
# ###################################################################### #
def setLocalTime ( dstOffset ):
  # get the YEAR to use in calculation
  year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()
  
  if year < 2020:
    # probably just booted, so get the time for calculation
    now=ntptime.time()
    # reload current time 
    year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()

  # szTime = "{:4}-{:02}-{:02} {:02}:{:02}:{:02}".format( year, month, day, hour, minute, second )
  # print( "Time : " , szTime )

# define DST change dates for this year
  # NZDT Starts : 2:00 Last Sunday September 
  dstDT = utime.mktime((year, 9, (30 -(int(5*year/4+4))%7),2,0,0,0,0,0)) #Time of September change to NZDT
  # NZST Starts : 3:00 1st Sunday April 
  dstST = utime.mktime((year, 4, ( 7 -(int(5*year/4+5))%7),3,0,0,0,0,0)) #Time of April change to NZST
    
  if dstOffset >= 0 : # 
    # print( "Positive DST timezones" )
    if now > dstST and now < dstDT:
      # print( "Standard Time")
      ntptime.NTP_DELTA = 3155673600-( dstOffset * 3600) 
    else:
      # print( "Daylight Time")
      ntptime.NTP_DELTA = 3155673600-( (dstOffset+1) * 3600)
  else:
    # print( "Negative DST timezones" )
    if now > dstDT and now < dstST  :
      # print( "Standard Time")
      ntptime.NTP_DELTA = 3155673600-( dstOffset * 3600) 
    else:
      # print( "Daylight Time")
      ntptime.NTP_DELTA = 3155673600-( (dstOffset+1) * 3600)

  # set the RTC to correct time 
  ntptime.settime()
  # year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()
  # szTime = "{:4}-{:02}-{:02} {:02}:{:02}:{:02}".format( year, month, day, hour, minute, second )
  # print( "setTime : " , szTime )

[Divergentti]

the timzone had not bothered me with my projects until i made a neopixel clock and we switched to daylight savings recently.

So this is what I have come up with for my timezone calculations based on the input from the earlier posts by davef and enzo
The different months, March, April, September and October / first and last sunday all have a different offsets based so you will need to play around with those for your timezone. This has have been check against https://www.timeanddate.com/ for the NZ timezone up to 2030.

there is probably some additions that could be included but this met my needs for now

https://en.wikipedia.org/wiki/List_of_UTC_time_offsets
https://www.iana.org/time-zones

I basically run this code on boot, and once a day to keep the RTC in sync correctly

Code: Select all

# ###################################################################### #
# Set RTC localTime from UTC and apply DST offset
# Requires import machine, utime, ntptime
# assumes active network, otherwise will raise error whch is not currently dealt with
# Note: dstOffset should be between -12 and +14 
# ###################################################################### #
def setLocalTime ( dstOffset ):
  # get the YEAR to use in calculation
  year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()
  
  if year < 2020:
    # probably just booted, so get the time for calculation
    now=ntptime.time()
    # reload current time 
    year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()

  # szTime = "{:4}-{:02}-{:02} {:02}:{:02}:{:02}".format( year, month, day, hour, minute, second )
  # print( "Time : " , szTime )

# define DST change dates for this year
  # NZDT Starts : 2:00 Last Sunday September 
  dstDT = utime.mktime((year, 9, (30 -(int(5*year/4+4))%7),2,0,0,0,0,0)) #Time of September change to NZDT
  # NZST Starts : 3:00 1st Sunday April 
  dstST = utime.mktime((year, 4, ( 7 -(int(5*year/4+5))%7),3,0,0,0,0,0)) #Time of April change to NZST
    
  if dstOffset >= 0 : # 
    # print( "Positive DST timezones" )
    if now > dstST and now < dstDT:
      # print( "Standard Time")
      ntptime.NTP_DELTA = 3155673600-( dstOffset * 3600) 
    else:
      # print( "Daylight Time")
      ntptime.NTP_DELTA = 3155673600-( (dstOffset+1) * 3600)
  else:
    # print( "Negative DST timezones" )
    if now > dstDT and now < dstST  :
      # print( "Standard Time")
      ntptime.NTP_DELTA = 3155673600-( dstOffset * 3600) 
    else:
      # print( "Daylight Time")
      ntptime.NTP_DELTA = 3155673600-( (dstOffset+1) * 3600)

  # set the RTC to correct time 
  ntptime.settime()
  # year, month, day, hour, minute, second, ms, dayinyear = utime.localtime()
  # szTime = "{:4}-{:02}-{:02} {:02}:{:02}:{:02}".format( year, month, day, hour, minute, second )
  # print( "setTime : " , szTime )

I made this for Finland. I fixed second last in date tuple to 6, because 0 is Monday. TIMEZONE_DIFFERENCE is normal (winter) time difference, like 2 for Finland.

Global dst_on is needed for Suntime calculation, perhaps I change it so that timezone is not actually needed.

Code: Select all

def resolve_dst_and_set_time():
    global TIMEZONE_DIFFERENCE
    global dst_on
    # This is most stupid thing what humans can do!
    # Rules for Finland: DST ON: March last Sunday at 03:00 + 1h, DST OFF: October last Sunday at 04:00 - 1h
    # Sets localtime to DST localtime
    if network.WLAN(network.STA_IF).config('essid') == '':
        now = mktime(localtime())
        if DEBUG_ENABLED == 1:
            print("Network down! Can not set time from NTP!")
    else:
        now = ntptime.time()

    (year, month, mdate, hour, minute, second, wday, yday) = localtime(now)

    if year < 2020:
        if DEBUG_ENABLED == 1:
            print("Time not set correctly!")
        return False

    dstend = mktime((year, 10, (31 - (int(5 * year / 4 + 1)) % 7), 4, 0, 0, 0, 6, 0))
    dstbegin = mktime((year, 3, (31 - (int(5 * year / 4 + 4)) % 7), 3, 0, 0, 0, 6, 0)))

    if TIMEZONE_DIFFERENCE >= 0:
        if (now > dstbegin) and (now < dstend):
            dst_on = True
            ntptime.NTP_DELTA = 3155673600 - ((TIMEZONE_DIFFERENCE + 1) * 3600)
        else:
            dst_on = False
            ntptime.NTP_DELTA = 3155673600 - (TIMEZONE_DIFFERENCE * 3600)
    else:
        if (now > dstend) and (now < dstbegin):
            dst_on = False
            ntptime.NTP_DELTA = 3155673600 - (TIMEZONE_DIFFERENCE * 3600)
        else:
            dst_on = True
            ntptime.NTP_DELTA = 3155673600 - ((TIMEZONE_DIFFERENCE + 1) * 3600)
    if dst_on is None:
        if DEBUG_ENABLED == 1:
            print("DST calculation failed!")
            return False
    else:
        ntptime.settime()

[Divergentti]

What firmware are you guys using? I can't replicate this with firmware built today.

npttime.settime() error overflow converting long int to machine word

with ESP32, sys.version = 3.4.0

esp32-idf4-20200902-v1.13.bin

How to repeat? Execute multiple times ntptime.settime()

>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
>>> ntptime.settime()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ntptime.py", line 39, in settime
OverflowError: overflow converting long int to machine word
>>> ntptime.settime()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ntptime.py", line 35, in settime
File "ntptime.py", line 25, in time
OSError: [Errno 110] ETIMEDOUT
>>> ntptime.settime()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ntptime.py", line 35, in settime
File "ntptime.py", line 25, in time
OSError: [Errno 110] ETIMEDOUT
>>> ntptime.settime()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ntptime.py", line 35, in settime
File "ntptime.py", line 25, in time
OSError: [Errno 110] ETIMEDOUT


-----

Not related to ntphosts:

>>> ntptime.host = 'test.nothin.com'
>>> ntptime.settime()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ntptime.py", line 35, in settime
File "ntptime.py", line 20, in time
OSError: -202
>>>
>>>
>>>
>>> resolve_dst_and_set_time()
NTP time not set! Error -202
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "main.py", line 322, in resolve_dst_and_set_time
ValueError:
>>> resolve_dst_and_set_time()
NTP time not set! Error -202
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "main.py", line 322, in resolve_dst_and_set_time
ValueError:
>>> resolve_dst_and_set_time()
NTP time not set! Error -202
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "main.py", line 322, in resolve_dst_and_set_time
ValueError:
>>> ntptime.host = 'pool.ntp.org'
>>> resolve_dst_and_set_time()
>>> resolve_dst_and_set_time()
>>> ntptime.settime()
>>> ntptime.settime()
>>> localtime()
(2021, 2, 28, 10, 30, 40, 6, 59)

----

trying this:

Code: Select all

n = 0

    while (settime_complete is False) and (n <= 20):
        if n >= 20:
            f4.write("npttime.settime() tried 20 times. Giving up\n")
            f4.close()
            reset()
        else:
            try:
                ntptime.settime()
            except Exception as e:
                n += 1
                # npttime.settime() error overflow converting long int to machine word
                f4.write("npttime.settime() error %s\n" % e)
                sleep(10)
            settime_complete = True