1 TB stored for 1 month is 1 TBm, 1 TB stored for 1 hour is 1 TBh. 1 TBm = 720 TBh, given 30 days in a month. It’s similar to electricity, you have a device which uses 1 kW and let it run for 1 hour and it will use 1 kWh.
The graph shows one data point per day. It looks like you have ~ 1.1 TB stored, so it is ~ 26.4 TBh per day and after 25 days ~660 TBh…