PowerShell automatically converts date and time information in various formats. If you'd like to know what formats are recognized by PowerShell, how these formats are defined, and what else your current culture defines, here is a one-liner that dumps all of this:
PS> [System.Globalization.CultureInfo]::CurrentUICulture.DateTimeFormat AMDesignator : Calendar : System.Globalization.GregorianCalendar DateSeparator : . FirstDayOfWeek : Monday CalendarWeekRule : FirstFourDayWeek FullDateTimePattern : dddd, d. MMMM yyyy HH:mm:ss LongDatePattern : dddd, d. MMMM yyyy LongTimePattern : HH:mm:ss MonthDayPattern : dd MMMM PMDesignator : RFC1123Pattern : ddd, dd MMM yyyy HH':'mm':'ss 'GMT' ShortDatePattern : dd.MM.yyyy ShortTimePattern : HH:mm SortableDateTimePattern : yyyy'-'MM'-'dd'T'HH':'mm':'ss TimeSeparator : : UniversalSortableDateTimePattern : yyyy'-'MM'-'dd HH':'mm':'ss'Z' YearMonthPattern : MMMM yyyy AbbreviatedDayNames : {So, Mo, Di, Mi...} ShortestDayNames : {So, Mo, Di, Mi...} DayNames : {Sonntag, Montag, Dienstag, Mittwoch...} AbbreviatedMonthNames : {Jan, Feb, Mrz, Apr...} MonthNames : {Januar, Februar, März, April...} IsReadOnly : False NativeCalendarName : Gregorianischer Kalender AbbreviatedMonthGenitiveNames : {Jan, Feb, Mrz, Apr...} MonthGenitiveNames : {Januar, Februar, März, April...}
Any format defined here is a legal date and time format.
Note: When you cast a string to a DateTime type, PowerShell always uses the culture-invariant format. Your own culture is honored when you use the -as operator. That's why these two lines may produce different results if you're not on the en-US culture:
PS> [DateTime] '10/1/2013' Dienstag, 1. Oktober 2013 00:00:00 PS> '10/1/2013' -as [DateTime] Donnerstag, 10. Januar 2013 00:00:00
