Hi Alessio,
Greetings from Syncfusion.
We can render the stripLine in the x-axis repeatedly for
every midnight by setting the isRepeat property as true, repeatEvery
property as 24, sizeType as Hours and specify the size
property based on your requirement in stripLines property in primaryXAxis.
We have created an angular application to demonstrate the same. Please find the
below stackblitz link for your requirement.
Sample link: https://stackblitz.com/edit/angular-om6yk4?file=src%2Fapp.component.ts
Please find the below UG link for your reference.
UG link: https://ej2.syncfusion.com/angular/documentation/chart/strip-line#recurrence-stripline
Code Snippet:
stripLines: [{
startFromAxis: true, size: 5, sizeType: 'Hours', isRepeat: true, repeatEvery:
24, visible: true,
color: 'rgba(167,169,171, 0.3)'
}]
|
Screenshot:

Kindly, revert us if you have any concerns.
Regards,
Swetha