This is based on code in the Pretty and Humane date & time threads. I added handling for "last Monday, 5pm", because I like that more than x days ago. This handles past and future up to centuries. I am keen on the internationalization aspect so this needs a lot more work eventually. Calculations are in the local time zone.
public static class DateTimePretty
{
private const int SECOND = 1;
private const int MINUTE = 60 * SECOND;
private const int HOUR = 60 * MINUTE;
private const int DAY = 24 * HOUR;
private const int WEEK = 7 * DAY;
private const int MONTH = 30 * DAY;
private const int YEAR = 365;
const string now = "just now";
const string secondsFuture = "in {0} seconds", secondsPast = "{0} seconds ago";
const string minuteFuture = "in about a minute", minutePast = "about a minute ago";
const string minutesFuture = "in about {0} minutes", minutesPast = "about {0} minutes ago";
const string hourFuture = "in about an hour", hourPast = "about an hour ago";
const string hoursFuture = "in about {0} hours", hoursPast = "about {0} hours ago";
const string tomorrow = "tomorrow, {0}", yesterday = "yesterday, {0}";
const string nextDay = "{0}", nextWeekDay = "next {0}", lastDay = "last {0}";
//const string daysFuture = "in about {0} days", daysPast = "about {0} days ago";
const string weekFuture = "in about a week", weekPast = "about a week ago";
const string weeksFuture = "in about {0} weeks", weeksPast = "about {0} weeks ago";
const string monthFuture = "in about a month", monthPast = "about a month ago";
const string monthsFuture = "in about {0} months", monthsPast = "about {0} months ago";
const string yearFuture = "in about a year", yearPast = "about a year ago";
const string yearsFuture = "in about {0} years", yearsPast = "about {0} years ago";
const string centuryFuture = "in about a century", centuryPast = "about a century ago";
const string centuriesFuture = "in about {0} centuries", centuriesPast = "about {0} centuries ago";
/// <summary>
/// Returns a pretty version of the provided DateTime: "42 years ago", or "in 9 months".
/// </summary>
/// <param name="dateTime">DateTime in local time format, not Utc</param>
/// <returns>A pretty string</returns>
public static string GetPrettyDate(DateTime dateTime)
{
DateTime dateTimeNow = DateTime.Now;
bool isFuture = (dateTimeNow.Ticks < dateTime.Ticks);
var ts = isFuture ? new TimeSpan(dateTime.Ticks - dateTimeNow.Ticks) : new TimeSpan(dateTimeNow.Ticks - dateTime.Ticks);
double delta = ts.TotalSeconds;
if (delta < 10)
return now;
if (delta < 1 * MINUTE)
return isFuture ? string.Format(secondsFuture, ts.Seconds) : string.Format(secondsPast, ts.Seconds);
if (delta < 2 * MINUTE)
return isFuture ? minuteFuture : minutePast;
if (delta < 45 * MINUTE)
return isFuture ? string.Format(minutesFuture, ts.Minutes) : string.Format(minutesPast, ts.Minutes);
if (delta < 2 * HOUR)
return isFuture ? hourFuture : hourPast;
if (delta < 7 * DAY)
{
string shortTime = DateTimeFormatInfo.CurrentInfo.ShortTimePattern;
string shortWeekdayTime = "dddd, " + shortTime;
int dtDay = (int) dateTime.DayOfWeek;
int nowDay = (int) dateTimeNow.DayOfWeek;
if (isFuture)
{
if (dtDay == nowDay)
{
if (delta < DAY)
return string.Format(hoursFuture, ts.Hours);
else
return string.Format(nextWeekDay, dateTime.ToString(shortWeekdayTime));
}
else if (dtDay - nowDay == 1 || dtDay - nowDay == -6)
return string.Format(tomorrow, dateTime.ToString(shortTime));
else
return string.Format(nextDay, dateTime.ToString(shortWeekdayTime));
}
else
{
if (dtDay == nowDay)
{
if (delta < DAY)
return string.Format(hoursPast, ts.Hours);
else
return string.Format(lastDay, dateTime.ToString(shortWeekdayTime));
}
else if (nowDay - dtDay == 1 || nowDay - dtDay == -6)
return string.Format(yesterday, dateTime.ToString(shortTime));
else
return string.Format(lastDay, dateTime.ToString(shortWeekdayTime));
}
}
//if (delta < 7 * DAY)
// return isFuture ? string.Format(daysFuture, ts.Days) : string.Format(daysPast, ts.Days);
if (delta < 4 * WEEK)
{
int weeks = Convert.ToInt32(Math.Floor((double) ts.Days / 30));
if (weeks <= 1)
return isFuture ? weekFuture : weekPast;
else
return isFuture ? string.Format(weeksFuture, weeks) : string.Format(weeksPast, weeks);
}
if (delta < 12 * MONTH)
{
int months = Convert.ToInt32(Math.Floor((double) ts.Days / 30));
if (months <= 1)
return isFuture ? monthFuture : monthPast;
else
return isFuture ? string.Format(monthsFuture, months) : string.Format(monthsPast, months);
}
// Switch to days to avoid overflow
delta = ts.TotalDays;
if (delta < 100 * YEAR)
{
int years = Convert.ToInt32(Math.Floor((double) ts.TotalDays / 365.25));
if (years <= 1)
return isFuture ? yearFuture : yearPast;
else
return isFuture ? string.Format(yearsFuture, years) : string.Format(yearsPast, years);
}
else
{
int centuries = Convert.ToInt32(Math.Floor((double) ts.TotalDays / 365.2425));
if (centuries <= 1)
return isFuture ? centuryFuture : centuryPast;
else
return isFuture ? string.Format(centuriesFuture, centuries) : string.Format(centuriesPast, centuries);
}
}
}
