How do I convert this Time integer to a Date in Ruby?
How to convert a unix timestamp (seconds since epoch) to Ruby DateTime?
I'm trying to update my system using apt-get, but it's giving me this error  Err http://bd.archive.ubuntu.com raring Release.gpg          Could not connect to bd.archive.ubuntu.com:80 (116.193.170.18), connection timed out Err http://bd.archive.ubuntu.com raring-updates Release.gpg   Unable to connect to bd.archive.ubuntu.com:http: Err http://bd.archive.ubuntu.com raring-backports Release.gpg   Unable to connect to bd.archive.ubuntu.com:http: Reading package lists... Done W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/dists/raring/Release.gpg  Could not connect to bd.archive.ubuntu.com:80 (116.193.170.18), connection timed out W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/dists/raring-updates/Release.gpg  Unable to connect to bd.archive.ubuntu.com:http: W: Failed to fetch http://bd.archive.ubuntu.com/ubuntu/dists/raring-backports/Release.gpg  Unable to connect to bd.archive.ubuntu.com:http: W: Some index files failed to download. They have been ignored, or old ones used instead.   I am not a Ubuntu master but I can understand this is not a computer error. Any clues on how to fix it? INSERT takes over 5 hours, when inserting more than specific number of rows When inserting less then about 1,350,000 rows to the table it all takes about 2 minutes, however when number of inserted rows is bigger, then the time needed to insert data grows to about 5 hours.  The problem is not connected with query or indexes, because everything has been working fine for a long time and nothing has changed in the structure of query, tables or indexes.   Problem appeared for the first time about 2 weeks ago and it appears repeatedly on days, when number of inserted rows is bigger than +-1,350,000. For example on one day number of inserted rows is 1,200,000 and the process takes 2 minutes, on the other day number of rows is 1,450,000 and it takes 5-6 hours to insert data.  I tried to rebuild indexes, but it has not helped. Show that $ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$ I need a hand in showing that $$ \sum_{n=2}^m \binom{n}{2} = \binom{m+1}{3}$$   Thanks in advance for any help. With the enthusiastic question of "Who wants ice-cream?", what is the more correct response?         (Not) I.   (Not) me.      Neither response is a sentence. The first response of "(not) I" sounds stuffy, like it should be followed with an indignant sniff. The second sounds like American idiom and acceptable for casual speech.    What do you say? Safely moving and creating new tempdb files Two things I'd like to know:   how do you safely move tempdb with minimal downtime? how many tempdb files do you need?   Is it 1 file per core? So quad-core = 4 tempdb files, creating three new ones? Make Launchpad Appear on screen with mouse Selecting attributes or rows of polygons that intersect two attributes of overlaying polygon using ArcGIS Pro Proving the so-called "Well Ordering Principle" Why is the t-test designed for small samples? Raise bounty on question How to prevent unification when animating in photoshop? I am trying to create an animated gif where text drops down and smashes into the background and cracks it. Whenever I try and transform it though, the transformation is applied to all frames. How do I prevent this? I'm using Adobe Photoshop CS6 (64-bit) surjective immersion $\mathbb{R}^2 \to \mathbb{R}^2$ which is not a diffeomorphism Does there exist a surjective immersion $\mathbb{R}^2 \to \mathbb{R}^2$ which is not a diffeomorphism?  I tried to modify $\exp: \mathbb{C} \to \mathbb{C}$ to be surjective, but I find it hard to preserve the property of being immersion.  I also noticed that if we replace $\mathbb{R}^2$ with $S^2$ or any other compact simply connected manifold, no such immersion exists, because then it would be a covering map (as a local diffeomorphism from compact space, thus proper), but since the manifold is simply connected, it must be a diffeomorphism. How do you read CSS rule values with JavaScript? How can I convert a hex string to a byte array? Is it possible and furthermore constructive to make LaTeX automatically format specific words in specific way? Let's say, for example, I'd like to have every occurrence of the word "hello" in a bold cyan monospaced font, whereas the rest of the document remains normal, sans serif and black.   How can I achieve that without having to do a search&amp;replace to place "hello" into a custom command every time before I compile the .tex file? How do I put /home in a different partition? Yeah, so I have 2 hard drives, on with 2 partitions(backups and windows), and I have another that also has 2 partitions with only one used. I have Ubuntu on hard drive 2:partition one, but I have come to a point when the /home folder can't hold any more files, but the partition is only about 15% filled up. So I did some researching and figured out that you can put it on a separate partition, but most of the guides were vague on what I needed to do. Could someone give me step-by-step instructions on what I need to do, or even tell me a, easier or different way to fix this /home folder capacity problem? Solve recurrence relation $ a_{n+1} = (n+1)a_n + 1 $ $a_0 = 1 \\ a_{n+1} = (n+1)a_n + 1 $  Could you help me solve this? And maybe someone know good source explaining how to solve recurrence relations? Why does the question's closed status disappear when clicking to load a new edit? I've come across a small issue which occurs when a question has been closed but the question itself or one of its answers are being edited.  Steps to reproduce:   Visit a closed question. (even closed years ago)   In a different tab or browser, edit the question or one of its answers. "an edit has been made to this post; click to load" message will appear above the edited post in the first tab/browser, click it. The .question-status div becomes hidden, which includes the closed notice below a question and, for a duplicate-closed question, the list of duplicates above the question body. This gives the appearance that the question is no longer closed (until you refresh).   Some screenshots:                I know it isn't common/important but it did confuse me when looking at a particularly bad question - I thought it had been reopened.   Is this an intentional feature? If so, what was the thinking behind it?    Another example  Before    After Is there a preinstalled or automatic firewall? Does Ubuntu come with a preinstalled or automatic firewall? If not, do I need one?   I've read some articles about the advantages of Linux over other operating systems about security (no need to have antivirus, ...) but would like to be sure. $g^k$ is a primitive element modulo $m$ iff $\gcd (k,\varphi(m))=1$