Hi Almis,
#Regarding customize the header in sfschedule
Your requirement can be achieved with the help of Custom Header in SfSchedule. we have already documentation about ‘How to create custom header in Xamarin.Forms Schedule’ in our Syncfusion Knowledge base in our website. Please refer to the following KB link for your reference.
Please let us know if you have any concerns.
Regards,
SaiGanesh Sakthivel