[BUG] - switching daylight saving time doesn't work

[wolfgang-braun]

Describe the bug

Task gets executed an hour too late. Local time / location is correctly set.

To Reproduce

	location, err := time.LoadLocation("Europe/Berlin")
	if err != nil {
		panic(err)
	}
	s := gocron.NewScheduler(location)
	s.Every(1).Day().At("09:00").Do(logLocalTime)

Output:

2022/03/28 10:00:00 - logging local time: 2022-03-28 10:00:00

Expected behavior

2022/03/28 09:00:00 - logging local time: 2022-03-28 09:00:00

Version

github.com/go-co-op/gocron v1.13.0

Other

• go 1.17
• Docker container has been restarted after time change
• Docker image:

FROM scratch
COPY --from=builder /usr/share/zoneinfo /usr/share/zoneinfo
COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
COPY --from=builder /service /service
COPY --from=builder /logs /logs
COPY --from=builder /data /data
ENV TZ Europe/Berlin
ENTRYPOINT ["/service"]

Related

• [BUG] - switch from daylight saving time to standard time causes problem #69

Thank you!

[JohnRoesler]

hey @wolfgang-braun thanks for reporting. An hour sounds a lot like a daylight time issue. Does Europe/Berlin use daylight time?

[wolfgang-braun]

Hi @JohnRoesler, yes it does. The switch was on Sunday. Using the former maintainers package a container restart did the trick.
I now switched to go 1.18 and the latest go alpine docker image and will check whether the issue persists.

Furthermore I can't reproduce it using playground

package main

import (
	"log"
	"time"

	"github.com/go-co-op/gocron"
)

func main() {
	location, err := time.LoadLocation("Europe/Berlin")
	if err != nil {
		panic(err)
	}
	logLocalTime(location)
	s := gocron.NewScheduler(location)
	s.Every(1).Day().At("00:00:05").Do(logLocalTime, location)
	s.StartBlocking()
}

func logLocalTime(location *time.Location) {
	log.Println("Europe/Berlin time: ", time.Now().In(location).Format("2006-01-02 15:04:05"))
}

2009/11/10 23:00:00 Europe/Berlin time:  2009-11-11 00:00:00
2009/11/10 23:00:05 Europe/Berlin time:  2009-11-11 00:00:05

This behavior is actually expected: .At("00:00:05") prints 2009-11-11 00:00:05 while the system/application time is 2009/11/10 23:00:05

One difference compared to my use case is that system/application time zone = cron time zone.

[franklinkim]

Can confirm the behaviour, ran into the same issue.

[JohnRoesler]

Did this resolve? We had a similar issue a while ago that was related to the underlying docker container the app was being run in. I'm inclined to suspect something with the host system's time / tz files being the cause of this issue.

[JohnRoesler]

reopen if this is still an issue