(or emacs irrelevant)

Time flies

This is the 15th post on this blog. Thankfully, no heart attacks after the 13th one or anything. So I'll commemorate it with a post on dealing with dates in calc.

How much time has passed since I started this blog?

  1. Open calc with C-x **:

    --- Emacs Calculator Mode ---
        .
    
  2. Enter 20 Dec 2014 with '<12 20 14RET:

    --- Emacs Calculator Mode ---
    1:  <Sat Dec 20, 2014>
        .
    
  3. Enter current time with tN:

    --- Emacs Calculator Mode ---
    2:  <Sat Dec 20, 2014>
    1:  <11:56:27am Sat Jan 3, 2015>
        .
    
  4. Subtract with -:

    --- Emacs Calculator Mode ---
    1:  -14.498044
        .
    

This means that, if I want to maintain my one-post-per-day streak, I still have half of a day to post this. Unfortunately, I have only an old version of the blog repository on this machine, and the current one is on a laptop at home. So I'll post this in the evening.

Did you know what 2015 looks like in binary?

In your current calc session,

  1. Enter 2015 SPC:

    --- Emacs Calculator Mode ---
    2:  -14.498044
    1:  2015
        .
    
  2. Switch to binary with d2:

    --- Emacs Calculator Mode ---
    2:  -2#1110.011111110111111111001111110001
    1:  2#11111011111
    .
    
  3. Wow, a palindrome. It's too spooky, switch back to decimal with d0:

    --- Emacs Calculator Mode ---
    2:  -14.498044
    1:  2015
        .
    

If you're new to calc, you'll probably wonder why you can't enter negative numbers with -. It can be done with _, just like in J. Find out more in the info; the interactive tutorial is absolutely excellent.