Scheduled Modify Simple Queue using script

In my router there are almost 500 simple queue.
I want to allocate 2 Mbps upload and download during 8 am to 2 pm & 1 Mbps upload and download during 2 pm to 8 am.
Please help me to do this with script and scheduled task.
Im a beginner, so if you can help me with a sample script then it will be much appreciated.
Thank you in advance