// where to start from, expressed as an offset in hours from now
$rough_start=time()+$leases_offset*3600;
-// show the next 36 grains
$duration=$leases_slots*$leases_granularity;
$steps=$duration/$leases_granularity;
$start=intval($rough_start/$leases_granularity)*$leases_granularity;