SYMPTOM:
Consider that a Report Services document has two dynamic text boxes in its header section corresponding to EXECUTIONTIME and DATETIME autotexts as shown:

When this document is executed in PDF mode from Strategy Developer 9.x on the Strategy Intelligence Server 9.x machine, the dynamic text box corresponding to EXECUTIONTIME autotext shows incorrect timestamp:

CAUSE:
This is a known issue with Strategy Developer 9.x.
ACTION:
Strategy will continue to investigate and post updates as soon as they are available.
WORKAROUND:
Use Strategy Web 9.x which shows the correct timestamp for the EXECUTIONTIME autotext:

If Strategy Developer 9.x has to be used then the DATETIME autotext can be used which returns expected results as indicated above.