How to set date and time?

Could you please elaborate on the steps to set the date and time on a device, such as a smartphone, computer, or smartwatch? It's often essential to ensure that our devices are displaying the correct time and date, but the process can vary depending on the device and its operating system. Are there any general guidelines or specific steps that apply across different devices? Additionally, what are some potential issues that might arise when trying to adjust the date and time, and how can they be resolved?