← index #1274Issue #16490
Related · medium · value 0.734
QUERY · ISSUE

Need to address inconsistencies between mktime and localtime.

openby dhylandsopened 2015-05-20updated 2024-09-08
needs-info

Currently, if I do:

>>> time.localtime(-1072915200)
(1966, 1, 1, 0, 0, 0, 5, 1)
>>> time.mktime((1966, 1, 1, 0, 0, 0, 5, 1))
3222052096
>>> time.localtime(3222052096)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OverflowError: overflow converting long int to machine word
>>> hex(3222052096)
'0xc00c9d00'
>>> hex(0x80000000 - 1072915200)
'0x400c9d00'

I think that time.mktime((1966, 1, 1, 0, 0, 0, 5, 1)) should return the negative representation. However, I noticed that timeutils_seconds_since_2000 returns an mp_uint_t rather than an mp_int_t

So a couple of questions came to mind:
1 - Do we want to support times from 1966 to 2000 (which is the -ve small int range)?
2 - Should we support mpz ints?
3 - Adding full support for mpz ints seems like overkill, but we could get 1 extra bit by allowing mpz ints in the full 32-bit range to be supported. Then we'd be able to support dates from 2000 +/- 68 years. This would only require a slightly different conversion into and out of the timeutils functions. The actual code itself wouldn't need to change.

Thoughts?

CANDIDATE · ISSUE

time.mktime() returns incorrect Unix timestamp on ESP32

openby jurijpopened 2024-12-28updated 2025-11-06
docs

Port, board and/or hardware

sysname='esp32', nodename='esp32', release='1.24.1', version='v1.24.1 on 2024-11-29', machine='Generic ESP32 module with ESP32. Unique ID b'\x94\xe6\x86\x13o$' (not sure what this is

MicroPython version

release='1.24.1', version='v1.24.1 on 2024-11-29',
When using this board and setting time using the ntp library thus ntptime.settime() this synchronizes the RTC to UTC using an NTP server, and it seems to be working correctly since time.localtime() returns (2024, 12, 28, 18, 11, 1, 5, 363) (UTC time). As I understand it, this should reset the real time clock to the current time. If I then set time.mktime(time.localtime()) which should provide the Unix time, it does not, instead is spits out 788726670 which is 1994-12-29 18:44:30 UTC. Can someone please explain this ? Is it a a bug? Bottom line, how can the realtime clock be set to a specific time?

Reproduction

from machine import RTC
import time

Manually set the RTC to a known time (e.g., 2024-01-28 15:30:00 UTC)

rtc = RTC()
rtc.datetime((2024, 1, 28, 0, 15, 30, 0, 0)) # (year, month, day, weekday, hour, minute, second, subseconds)

Get the Unix timestamp

unix_time = time.mktime(time.localtime())

print("Unix time:", unix_time)

Result: Unix time: 759771000 it should be closer to 1735413856.203176

Expected behaviour

Expected the unix time to be determined correctly. That is it should look something like this 1735413022.697727

Observed behaviour

The output is incorrect - see Expected behaviour result above

Additional Information

No, I've provided everything above.

Code of Conduct

Yes, I agree

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