c# - Getting invalid month names in DateTime formatting -

i have simple program return day , shortdate. example, if input 27th march 2016, output "sun, 03/27/2016"

string shortmonthformat = "ddd"; datetime dtc = convert.todatetime("2016-03-27 12:26:41.210"); string result = dtc.tostring(string.format("{0}, {1}", shortmonthformat, dtc.toshortdatestring())); console.writeline(result); console.readline(); 

this code works current system date format mm/dd/yyyy(03/27/2016). if system's date format changed dd-mmm-yy(27-mar-16), code returning following output "sun, 27-3ar-16"

mar(march) returned "3ar"

aug(august) becomes "aua.d."

why happening?

because m format specifier meaning single digit month number 1 12 , g specifier means period or era such a.d.

since other characters doesn't referring any format specifiers, reflected output exactly are.

by way, code seems little bit complicated , buggy. first, generate format using shortmonthformat , toshortdatestring , generate string representation of datetime that formatted string.

that's why code looks like;

string result = dtc.tostring("ddd, 27-mar-16"); 

which not too sense.

you can fix code use shortdatepattern property of currentculture instead of use dtc.toshortdatestring() like;

string result = dtc.tostring(string.format("{0}, {1}",                               shortmonthformat,                               cultureinfo.currentculture.datetimeformat.shortdatepattern)); 

by way, based on variable name (which shortmonthformat), ddd specifier abbreviated day names. if wanna abbreviated month names, can use mmm specifier instead.

string shortmonthformat = "mmm";