RTC time greater than 24 hours

[AlfRomeo]

Hello everyone, I am using an internal RTC on STM32L431. After running for 23:59:59 seconds, the time changes to 24:00:00 instead of 00:00:00, and the week day has not been incremented. Why is this?

[Sarra.S]

Hello @AlfRomeo, 

Is the RTC correctly configured to use the 24-hour format? 

[waclawek.jan]

As @Sarra.S said above, you probably have set the RTC inadvertently to 12 hour format, probably because of uninitialized struct when calling Cube/HAL functions setting time.

JW

[AlfRomeo]

The format of the hour is still 24 hours, and I haven't changed it

[Uwe Bonnes]

Does the RTC continue with 24:01 ? Otherwise, where is the problem?

[Andrew Neil]

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@Uwe Bonnes wrote:

Otherwise, where is the problem?

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24:00 is never a valid time - it should go from 23:59:59.999 to 00:00

[Andrew Neil]

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@AlfRomeo wrote:

The format of the hour is still 24 hours, and I haven't changed it

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Did you follow @waclawek.jan's link - to details about the issues with uninitialised or incompletely-initialised config structures?

[waclawek.jan]

> The format of the hour is still 24 hours, and I haven't changed it

Read out and check/post the RTC registers content.

JW

[AlfRomeo]

At the time of debugging, the time continued to run after 24:00:00 seconds and changed to 00:00:00 after 39:59:59 seconds, but the week did not increase

[AlfRomeo]

不知道为什么，但是停电后重置后，它又好转了。该代码没有更改任何内容，除了在获取 clock 时在 hour， minute， and second 之后执行模运算。其他一切都没有改变。起初，更改此设置后，问题仍然存在，没有停电。然而，停电后，问题消失了，我感到非常困惑