How do I calculate someone's age in C#?
Given a DateTime representing their birthday, how do I calculate someone's age? ...
datetime
How do I calculate relative time?
Given a specific DateTime value, how do I display relative time, like 2 hours ago 3 days ago a month ago etc, etc...? ...
What's the BEST way to remove the time portion of a datetime value (SQL Server)
Here's what I use: SELECT CAST(FLOOR(CAST(getdate() as FLOAT)) as DATETIME) I'm thinking there may be a better/more elegant way. Requirements: - It has to be as fast as possible (the less casting the better) - Final result has to be a datetime type, not a string ...
Best method for varchar date validation in Sybase (T-SQL)?
I have a stored procedure which takes as its parameter a varchar which needs to be cast as a datetime for later use: SET @the_date = CAST(@date_string AS DATETIME) I'm expecting the date string to be supplied in the format "DD-MON-YYYY", but in an effort to code defensively, if for some reason it can't be cast successfully, I want to ...
HOWTO - Compare a date string to datetime in SQL Server?
In SQL Server I have a DATETIME column which includes a time element. Example: '14 AUG 2008 14:23:019' What is the best method to only select the records for a particular day, ignoring the time part? Example: (Not safe, as it does not match the time part and returns no rows) DECLARE @p_date DATETIME SET @p_date = CONVERT(...
How do I parse and convert DateTime's to the RFC 3339 date-time format?
How do I convert a DateTime structure to its equivalent RFC 3339 formatted string representation and/or parse this string representation back to a DateTime structure? The RFC-3339 date-time format is used in a number of specifications such as the Atom Syndication Format. ...
Dealing with PHP server and MySQL server in different time zones
For those of us who use standard shared hosting packages, such as GoDaddy or Network Solutions, how do you handle datetime conversions when your hosting server (PHP) and MySQL server are in different time zones? Also, does anybody have some best practice advice for determining what time zone a visitor to your site is in and manipulating...
Why does this python date/time conversion seem wrong?
>>> import time >>> time.strptime("01-31-2009", "%m-%d-%Y") (2009, 1, 31, 0, 0, 0, 5, 31, -1) >>> time.mktime((2009, 1, 31, 0, 0, 0, 5, 31, -1)) 1233378000.0 >>> 60*60*24 # seconds in a day 86400 >>> 1233378000.0 / 86400 14275.208333333334 time.mktime should return the number of seconds since the epoch. Since I'm giving it a time at mi...
What's a good way to check if two datetimes are on the same calendar day in TSQL?
Here is the issue I am having: I have a large query that needs to compare datetimes in the where clause to see if two dates are on the same day. My current solution, which sucks, is to send the datetimes into a UDF to convert them to midnight of the same day, and then check those dates for equality. When it comes to the query plan, thi...
Natural language date/time parser for .NET?
Does anyone know of a .NET date/time parser similar to Chronic for Ruby (handles stuff like "tomorrow" or "3pm next thursday")? Note: I do write Ruby (which is how I know about Chronic) but this project must use .NET. ...
SQL Server DateTime conversion failure
I have a large table with 1 million+ records. Unfortunately, the person who created the table decided to put dates in a varchar(50) field. I need to do a simple date comparison - datediff(dd, convert(datetime, lastUpdate, 100), getDate()) < 31 But it fails on the convert(): Conversion failed when converting datetime from character s...
Is DateTime.Now the best way to measure a function's performance?
I need to find a bottleneck and need to accurately as possible measure time. Is the following Code Snippet the best way to measure the performance? DateTime startTime = DateTime.Now; // Some Execution Process DateTime endTime = DateTime.Now; TimeSpan totalTimeTaken = endTime.Subtract(startTime); ...
How can I get the DateTime for the Start of the Week?
How do I find the Start of the week (Both Sunday and Monday) knowing just the current time in C#.NET Something like: DateTime.Now.StartWeek(Monday); ...
Datetime arithmetic with a string in Ruby
In Ruby, I'm trying to do the following. def self.stats(since) return Events.find(:all, :select => 'count(*) as this_count', :conditions => ['Date(event_date) >= ?', (Time.now - since)]).first.this_count end where "since" is a string representing an amount of time ('1 hour', '1 day', '3 days') and so on. Any suggestions? ...
What's a good way to overwrite DateTime.Now during testing?
I've got some (C#) code that relies on today's date to correctly calculate things in the future. If I use today's date in the testing, I have to repeat the calculation in the test, which doesn't feel right. What's the best way to set the date to a known value within the test so that I can test that the result is a known value? ...
Best way to convert DateTime to "n Hours Ago" in SQL
I wrote a SQL function to convert a datetime value in SQL to a friendlier "n Hours Ago" or "n Days Ago" etc type of message. And I was wondering if there was a better way to do it. (Yes I know "don't do it in SQL" but for design reasons I have to do it this way). Here is the function I've written: CREATE FUNCTION dbo.GetFriendlyDateT...
What is the simplest way to find the difference between 2 times in python?
I have 2 time values which have the type datetime.time. I want to find their difference. The obvious thing to do is t1 - t2, but this doesn't work. It works for objects of type datetime.datetime but not for datetime.time. So what is the best way to do this? ...
Dynamic regex for date time formats
Is there an existing solution to create regular expressions dynamically out of given date time format pattern? Supported date time format pattern does not matter (Joda DateTimeFormat, java.text.SimpleDateTimeFormat or others). i.e. for a given date-time format (for example "dd/MM/yyyy hh:mm"), it will generate corresponding regular exp...
.NET Date Const (with Globalization)
Does anyone know of a way to declare a date constant that is compatible with international dates? Ive tried: public const ADate as Date = #12/31/04# - not international compatible public shared readonly ADate As New Date(12, 31, 04) - breaking change if you have an optional parameter that defaults to this value because it isnt constant...
C# Casting vs. Parse
This may seem rudimentary to some, but this question has been nagging at me and as I write some code, I figured I would ask. Which of the following is better code in c# and why? ((DateTime)g[0]["MyUntypedDateField"]).ToShortDateString() or DateTime.Parse(g[0]["MyUntypedDateField"].ToString()).ToShortDateString() Ultimately, is it ...