The date and timestamp on the WSS Agent (WSSA) and Unified Agent (UA) installers are updated continually and a rolling date is used for display. This is a cosmetic issue and is not an accurate reflection of when the customer specific .msi installer was stamped. Customer's .msi installers will retain the same build number and binary it had been previously when it was stamped, but the date displayed in the Web Security Service (WSS) portal will be incorrect.
Web Security Service
This bug is currently being investigated. Once a resolution is determined it will be deployed in future WSS portal updates.