Good morning userswkbabyu,
I hope you are having an awesome weekend so far! Where were you trying to change your start date? At first I thought maybe your Fiscal Year but then quickly realized that wouldn't make sense because we are only dealing with January so I thought maybe it was in regards to something else.
In most areas inside QuickBooks Online we will have a filter icon in which we can set different dates. For the most part date change options are in the top left hand corner of transactions or reports.
Look forward to hearing from you.
Kindest Regards,
Lourdes Fernandez