jsf - primefaces calender: how to set dynamically mindate -

i have 2 primefaces calender controls.i want when select date first calender next calender mindate should start 1st calender's selected date.for instance, have selected 7/5/2013 next calender should disable dates before 8/5/2013
this have tried far not working

   <p:calendar id="fromd" value="#{requestcontroller.from}" yearrange="2013:2015" pattern="dd/mm/yyyy" mindate="#{requestcontroller.today}"/>  <p:calendar id="tod" value="#{requestcontroller.to}" yearrange="2013:2015" pattern="dd/mm/yyyy" mindate="#{requestcontroller.from}"/> 

any suggestions?

from change event , can't submit value of date.you need change event dateselect

<p:ajax event="dateselect" update="tod"/> 

it reset mindate next calender/component