By default, Backblaze's backup schedule is set to 'continuous'. Under this setting Backblaze will automatically backup your files 10 minutes after starting up your computer. As long as there are files selected for backup, Backblaze will continuously upload your files.
However, this does not mean that Backblaze continuously scans your computer for new files. We designed Backblaze to be lightweight, so it might take 3 hours to reflect new numbers and find your new files. The reason it takes 2 hours is that Backblaze runs VERY SLOWLY on purpose to try to keep the load off your CPU and disk. The result is that it can take up to 2 hours to detect any new files, or new hard drives, or if a file has changed, or a configuration has changed.
If you would like to force Backblaze to conduct an immediate rescan check out these helpful links bellow:
Additionally, you can manually change the backup schedule by following this guide.