From 4695a805752d95477c4a39a096afb6b1c7d06249 Mon Sep 17 00:00:00 2001
From: Jeffery Thompson <jeffery.thompson@wedoresi.com>
Date: Thu, 12 Dec 2019 14:58:00 -0500
Subject: [PATCH] feat: add DateTime extensions for add and wrap, like TimeSpan

---
 .../Extensions/DateTimeExtensions.cs          | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)

diff --git a/ICD.Common.Utils/Extensions/DateTimeExtensions.cs b/ICD.Common.Utils/Extensions/DateTimeExtensions.cs
index 34b5eb7..f813ce5 100644
--- a/ICD.Common.Utils/Extensions/DateTimeExtensions.cs
+++ b/ICD.Common.Utils/Extensions/DateTimeExtensions.cs
@@ -128,5 +128,92 @@ namespace ICD.Common.Utils.Extensions
 			TimeSpan diff = extends.ToUniversalTime() - origin;
 			return Math.Floor(diff.TotalSeconds);
 		}
+
+		/// <summary>
+		/// Adds the given number of hours to the time, wrapping every 24 hours without modifying the day.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="hours"></param>
+		/// <returns></returns>
+		public static DateTime AddYearsAndWrap(this DateTime extends, int years)
+		{
+			years += extends.Year;
+
+			// need to check days in month due to leap year
+			int daysInMonth = DateTime.DaysInMonth(years, extends.Month);
+			int day = daysInMonth < extends.Day ? daysInMonth : extends.Day;
+			return new DateTime(years, extends.Month, day, extends.Hour, extends.Minute, extends.Second, extends.Millisecond);
+		}
+
+		/// <summary>
+		/// Adds the given number of hours to the time, wrapping every 24 hours without modifying the day.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="months"></param>
+		/// <returns></returns>
+		public static DateTime AddMonthsAndWrap(this DateTime extends, int months)
+		{
+			months = MathUtils.Modulus(months + extends.Month - 1, 12) + 1;
+			int daysInMonth = DateTime.DaysInMonth(extends.Year, months);
+			int day = daysInMonth < extends.Day ? daysInMonth : extends.Day;
+
+			return new DateTime(extends.Year, months, day, extends.Hour, extends.Minute, extends.Second, extends.Millisecond);
+		}
+
+		/// <summary>
+		/// Adds the given number of hours to the time, wrapping every 24 hours without modifying the day.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="days"></param>
+		/// <returns></returns>
+		public static DateTime AddDaysAndWrap(this DateTime extends, int days)
+		{
+			days = MathUtils.Modulus(days + extends.Day - 1, DateTime.DaysInMonth(extends.Year, extends.Month)) + 1;
+			return new DateTime(extends.Year, extends.Month, days, extends.Hour, extends.Minute, extends.Second, extends.Millisecond);
+		}
+
+		/// <summary>
+		/// Adds the given number of hours to the time, wrapping every 24 hours without modifying the day.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="hours"></param>
+		/// <returns></returns>
+		public static DateTime AddHoursAndWrap(this DateTime extends, int hours)
+		{
+			hours = MathUtils.Modulus(hours + extends.Hour, 24);
+			return new DateTime(extends.Year, extends.Month, extends.Day, hours, extends.Minute, extends.Second, extends.Millisecond);
+		}
+
+		/// <summary>
+		/// Adds the given number of hours to the time, wrapping within the current 12 hour span, without modifying the day.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="hours"></param>
+		/// <returns></returns>
+		public static DateTime AddHoursAndWrap12Hour(this DateTime extends, int hours)
+		{
+			int currentHour = extends.Hour;
+			bool am = extends.Hour < 12;
+
+			int current12Hour = MathUtils.Modulus(currentHour, 12);
+			int new12Hour = MathUtils.Modulus(current12Hour + hours, 12);
+
+			return am
+				? new DateTime(extends.Year, extends.Month, extends.Day, new12Hour, extends.Minute, extends.Second, extends.Millisecond)
+				: new DateTime(extends.Year, extends.Month, extends.Day, new12Hour + 12, extends.Minute, extends.Second, extends.Millisecond);
+		}
+
+		/// <summary>
+		/// Adds the given number of minutes to the time, wrapping every 60 minutes without modifying the hour.
+		/// </summary>
+		/// <param name="extends"></param>
+		/// <param name="minutes"></param>
+		/// <returns></returns>
+		public static DateTime AddMinutesAndWrap(this DateTime extends, int minutes)
+		{
+			minutes = MathUtils.Modulus(minutes + extends.Minute, 60);
+			return new DateTime(extends.Year, extends.Month, extends.Day, extends.Hour, minutes, extends.Second, extends.Millisecond);
+		}
+	
 	}
 }