The config in this test lab will shape the upload on the internet traffic to 300mbit at normal hours, and to 100mbit between 20:00 to 21:00. To limit download is the same config by using police instead of shape and apply the service policy as input instead of output

Topology

Router-Config

time-range time-range_100mbit periodicdaily 20:00 to 21:00

Access-list 100 permit ip any any time-range time-range_100mbit

class-map match-all time-range_shape
    match access-group 100

policy-map internet_out
    class time-range_shape
        shapeaverage 100000k
    class class-default
        shapeaverage 300000k
policy-map exit

interface gigabitEthernet 8
    service-policyoutput internet_out

Test Result from Iperf