In an array of dates how to find closest previous date from a given date?

Question

For example I have an array of 1000 dates for example 1-feb-201015-jan-199710-feb-200117-feb-2010 and so on....If date given is for exampl 15-feb-2010 I need to find closest previous date from given date. In this case correct answer should be 1-feb-2010. How to find this date? Thanx for help

Sebastian · Answer

One way would be: public DateTime? FindClosestDate(IEnumerable source DateTime target) { DateTime? result = null; var lowestDifference = TimeSpan.MaxValue; foreach (var date in source) { if (date >= target) continue; var difference = target - date; if (difference { lowestDifference = difference; result = date; } } return result; }