Parsing a date and/or time information is tricky because formatting depends on the regional settings. This is why PowerShell can convert date and time based on your regional settings or in a culture-neutral format. Let's assume this date:
PS> $date = '1/6/2013'
If you convert this to a datetime type, PowerShell always uses the culture-neutral format (US format), regardless of your regional settings. The output is shown here on a German system:
PS> [DateTime]$date Sonntag, 6. Januar 2013 00:00:00
To use your regional datetime format, use the Parse() method which is part of the DateTime type, like this:
PS> [DateTime]::Parse($date) Samstag, 1. Juni 2013 00:00:00
Alternately, you can use Get-Date and the -date parameter:
PS> Get-Date -Date $date Samstag, 1. Juni 2013 00:00:00