Hello,
make sure you specify the css or type of marked timespan:
scheduler.addMarkedTimespan({
"days":5,
"zones":[0,600,840,870,1020,1440],
type:"dhx_time_block",
"sections":{"week_unit":3}
}); After I specify the type and set an appropriate value for the sections property, your config seems working in basic example screencast.com/t/0vtrWsLsKPb
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