1) Disk Space is calculated every night. The admin contact is sent an email when the account is approaching the disk space limit (default is 80%) giving them enough time to resolve any disk usage issues or upgrade the account.
2) Traffic usage is calculated every night and reset on the 1st of each month. Just like with disk space the admin email address is warned when usage reached 80%.
3) A further breakdown on traffic usage on a month by month basis
4) More detailed breakdown on visitors, unique visitors and page hits, what web browsers are they using and which days receive the most traffic.