Magento获得本周的第一天

is there any way to get the first day of the current week according to the current customer locales settings?

The current date is:

$today = date("Y-m-d", Mage::getModel('core/date')->timestamp(time()));

The current first day of the week by server's settings is:

$firstDayOfWeek = date("Y-m-d", strtotime('this week', Mage::getModel('core/date')->timestamp(time())));

I'm using magento 1.7.* CE version.

I'm don't know much about magento but if you just need the timestamp then strtotime is quite nice for this.

$weekBeginning = date('Y-m-d', Mage::getModel('core/date')->timestamp(strtotime('last monday')));