License is not valid when Buddhist calendar is used

License is shown as invalid when a system uses Buddhist calendar (for example, Thai locale). This is because the current year (2012) according to the Buddhist calendar is 2555. Here's the error shown:

Tested on Windows 7

Steps to reproduce

1. Open "Region and Language" window by going to Control Panel > Clock, Language, and Region > Region and Language
2. Change the format into Thai (which is based on Buddhist calendar
3. Run Confluence installation and enter the license

Workaround
Change the Format to English in "Region and Language" window and restart Confluence