it .317 means milliseconds use SSS
NSDateFormatter *dateFormatter1 = [[NSDateFormatter alloc] init];
[dateFormatter1 setDateFormat:@"yyyy-MM-ddTHH:mm:ss.SSS"]; // or omit the timezone use `yyyy-MM-dd'T'HH:mm:ss.SSS`
NSDate *date = [dateFormatter1 dateFromString:dateString];