Timestamp format for Live.getLastVisitsDetails API

I want to get all the visit & action details by specifying timestamp,i used minTimestamp param for same , but it is not working.

I am passing date in 2012-06-10 10:00:00 format
I am using piwik 1.8.2

http://localhost/piwik/index.php?module=API&method=Live.getLastVisitsDetails&idSite=2&period=day&date=today&format=xml&token_auth=c0e024d9200b5705bc4804722636378a&translateColumnNames=1&minTimestamp=2012-06-10 10:00:00

What is format of minTimestamp parameter ?

It’s a timestamp ie a UNIX timestamp: Unix time - Wikipedia