Expression update for every week

[QSense]

Hello everyone ,

In my chart ı have two expressions one of them

count(IF(ISTEK_DURUM='Açık',ISTEK_DURUM))  (requests' statu : Open)

second expression

=Count({<ISTEK_ACISTARIHI2 = {"<=$(=Timestamp(Today() - 30, 'DD.MM.YYYY hh:mm:ss'))"},ISTEK_DURUM={'Açık'}>} ISTEK_ACISTARIHI2)

requests' statu open over 30 days

As you see below for each bagining of week , I want to display updated data but my second expression updates based on today not for every beginning of week

my date dimension is :

date(WeekStart(ISTEK_ACISTARIHI2),'DD.MM.YYYY')