Top timestamp frequently asked interview questions

How to get the unix timestamp in C#

I have had look around stackoverflow, and even looked at some of the suggested questions and none seem to answer, how do you get a unix timestamp in C#?

Source: (StackOverflow)

Java Timestamp - How can I create a Timestamp with the date 23/09/2007?

How can I create a Timestamp with the date 23/09/2007?

Source: (StackOverflow)

Alternative timestamping services for authenticode

We perform code signing and timestamping for all our production builds. Occasionally (usually when we are about to RTM (!) ) the timestamp server at verisign ("http://timestamp.verisign.com/scripts/timstamp.dll") decides to go offline intermittently.

Anyone got any suggestions as to what do do in this case?

Does the timestamp server have to be hosted by your root certification authority?
Are there any other network hosted timestamp servers we could use
instead of Verisign if their server is down? Suggestions for other highly available and free alternatives welcome :)

Source: (StackOverflow)

NOW() function in PHP

Is there a PHP function that returns the date & time in the same format as the MySQL function NOW()?

I know how to do it using date(), but I am asking if there is a function only for this.

For example to return:

2009-12-01 00:00:00

Source: (StackOverflow)

Best timestamp format for CSV/Excel?

I'm writing a CSV file. I need to write timestamps that are accurate at least to the second, and preferably to the millisecond. What's the best format for timestamps in a CSV file such that they can be parsed accurately and unambiguously by Excel with minimal user intervention?

Source: (StackOverflow)

In Ruby on Rails, what's the difference between DateTime, Timestamp, Time and Date?

In my experience, getting dates/times right when programming is always fraught with danger and difficulity.

Ruby and Rails have always eluded me on this one, if only due to the overwhelming number of options; I never have any idea which I should pick.

When I'm using Rails and looking at ActiveRecord datatypes I can find the following

:datetime, :timestamp, :time, and :date

and have no idea what the differences are or where the gotchas lurk.

What's the difference? What do you use them for?

(P.S. I'm using Rails3)

Source: (StackOverflow)

Function that creates a timestamp in c#

I was wondering, is there a way to create a timestamp in c# from a datetime? I need a millisecond precision value that also works in Compact Framework(saying that since DateTime.ToBinary() does not exist in CF).

My problem is that i want to store this value in a database agnostic way so i can sortby it later and find out which value is greater from another etc.

Source: (StackOverflow)

Create timestamp variable in bash script

I am trying to create a timestamp variable in a shell script to make the logging a little easier. I want to create the variable at the beginning of the script and have it print out the current time whenever I issue echo $timestamp. It proving to be more difficult then I thought. Here are some things I've tried:

timestamp="(date +"%T")" echo prints out (date +"%T")

timestamp="$(date +"%T")" echo prints the time when the variable was initialized.

Other things I've tried are just slight variations that didn't work any better. Does anyone know how to accomplish what I'm trying to do?

Source: (StackOverflow)

Java Date cut off time information

I have a Java Date object containing date and time information. I want to write a method that cuts off the time information so I only have the date left.

Example input:

2008-01-01 13:15:00

Expected output:

2008-01-01 00:00:00

Do you have a tip? I tried doing something like this:

(timestamp / (24 * 60 * 60 * 1000)) * (24 * 60 * 60 * 1000)

but I ran into problems with the timezone.

Source: (StackOverflow)

Creation timestamp and last update timestamp with Hibernate and MySQL

For a certain Hibernate entity we have a requirement to store its creation time and the last time it was updated. How would you design this?

What data types would you use in the database (assuming MySQL, possibly in a different timezone that the JVM)? Will the data types be timezone-aware?
What data types would you use in Java (Date, Calendar, long, ...)?
Whom would you make responsible for setting the timestamps—the database, the ORM framework (Hibernate), or the application programmer?
What annotations would you use for the mapping (e.g. @Temporal)?

I'm not only looking for a working solution, but for a safe and well-designed solution.

Source: (StackOverflow)

Ruby/Rails: converting a Date to a UNIX timestamp

How would I get a UNIX timestamp (number of seconds since 1970 GMT) from a Date object in a Rails app?

I know Time#to_i returns a timestamp, but doing Date#to_time and then getting the timestamp results in something that's off by about a month (not sure why...).

Any help is appreciated, thanks!

Edit: OK, I think I figured it out- I was processing a date several times in a loop, and each time the date was moved a little because of a time zone mismatch, ultimately leading to my timestamp being a month off. Still, I'd be interested in knowing if there's any way to do this without relying on Date#to_time.

Source: (StackOverflow)

Converting timestamp to time ago in PHP e.g 1 day ago, 2 days ago...

I am trying to convert a timestamp of the format 2009-09-12 20:57:19 and turn it into something like 3 minutes ago with PHP.

I found a useful script to do this, but I think it's looking for a different format to be used as the time variable. The script I'm wanting to modify to work with this format is:

function _ago($tm,$rcs = 0) {
    $cur_tm = time(); 
    $dif = $cur_tm-$tm;
    $pds = array('second','minute','hour','day','week','month','year','decade');
    $lngh = array(1,60,3600,86400,604800,2630880,31570560,315705600);

    for($v = sizeof($lngh)-1; ($v >= 0)&&(($no = $dif/$lngh[$v])<=1); $v--); if($v < 0) $v = 0; $_tm = $cur_tm-($dif%$lngh[$v]);
        $no = floor($no);
        if($no <> 1)
            $pds[$v] .='s';
        $x = sprintf("%d %s ",$no,$pds[$v]);
        if(($rcs == 1)&&($v >= 1)&&(($cur_tm-$_tm) > 0))
            $x .= time_ago($_tm);
        return $x;
    }

I think on those first few lines the script is trying to do something that looks like this (different date format math):

$dif = 1252809479 - 2009-09-12 20:57:19;

How would I go about converting my timestamp into that (unix?) format?

Source: (StackOverflow)

'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp error

I have a database table containing dates

 (`date` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00').

I'm using MySQL. From the program sometimes data is passed without the date to the database. So, the date value is auto assigned to 0000-00-00 00:00:00 when the table data is called with the date column it gives error

...'0000-00-00 00:00:00' can not be represented as java.sql.Timestamp.......

I tried to pass null value to the date when inserting data, but it gets assign to the current time.

Is there any way I can get the ResultSet without changing the table structure

thanks in advance

Source: (StackOverflow)

Which timestamp type should I choose in a PostgreSQL database?

I would like to define a best practice for storing timestamps in my Postgres database in the context of a multi-timezone project.

I can

choose TIMESTAMP WITHOUT TIME ZONE and remember which timezone was used at insertion time for this field
choose TIMESTAMP WITHOUT TIME ZONE and add another field which will contain the name of the timezone that was used at insertion time
choose TIMESTAMP WITH TIME ZONE and insert the timestamps accordingly

I have a slight preference for option 3 (timestamp with time zone) but would like to have an educated opinion on the matter.

Source: (StackOverflow)