Traffic overusage invoices are created on different dates for a Virtuozzo Container subscription:
Top > Account Director > Customer Manager > Customers > %customer% > Billing History
161559 Invoice LSUK33046 %subscription% 03-Feb-2014, 12:41 157839 Invoice LSUK32453 %subscription% 05-Jan-2014, 12:38
Traffic is calculated on a basis of a so called last billing date (a date when the traffic usage is reset and calculation starts over) and the current date. Subscription’s last billing date is updated incorrectly if the subscription is synchronized with the latest version of the hosting plan.
Such behavior was classified as the software issue PBAS-23921 and was fixed in OBAS 4.5.3 release.