bookingkit always distinguishes between booking date and performance date when displaying revenues.
Regarding the dashboard statistics, we present orders paid with vouchers in this way because it allows us to provide an overview of the total booking volume.
In other words, vouchers are displayed "twice," once as a voucher and once as revenue for the booking. If we were to record these revenues only on the day of voucher purchase in the statistics, orders completely paid with a voucher would show a revenue of €0 on that day (which would be the same as if you, as a provider, offered a 100% discount and thus a free booking. This would be misleading, so we chose this method of representation).
In the Statistics, revenue is also displayed based on the booking date.
In the Calendar, all prices are displayed based on the performance date.