charliepark

// date of easter, call function with the 4-digit year as argument

//function (a,b,c,d,e,f,g,h,i,j,k,l,m){return b=a%19,c=~~(a/100),d=a%100,e=~~(c/4),f=c%4,g=~~((c+8)/25),h=~~((c-g+1)/3),i=(19*b+c-e-h+15)%30,j=~~(d/4),k=d%4,l=(32+2*f+2*j-i-k)%7,m=~~((b+11*i+22*l)/451),a+"-"+~~((i+l-7*m+114)/31)+"-"+((i+l-7*m+114)%31+1)}
  function (y,a,b,c,h,l,n){return a=y%19,b=~~(y/100),c=y%100,h=(19*a+b-~~(b/4)-~~((b-~~((b+8)/25)+1)/3)+15)%30,l=(32+2*b%4+2*~~(c/4)-h-c%4)%7,n=h+l-7*~~((a+11*h+22*l)/451)+114,y+'-'+~~(n/31)+'-'+(n%31+1)}

// f(2013) -> "2013-3-31"
// f(2012) -> "2012-4-8
// f(1775) -> "1775-4-16"

charliepark

.customButton(@cHue: 201, @cSaturation: 1, @cLightness: .4, @cDelta: .1, @cMultiplier: 1.5) {
   .cTextColor(@a, @b) when (@a < .5) { color: #fff; .cAlphaShadow(0, -1, 1, 0, (@b * 3.3)); }
   .cTextColor(@a, @b) when (@a > .5) { color: #333; .cAlphaShadow(0, 1, 1, 255, (@b * 3.3)); }
   .cTextColor(@a) { -webkit-font-smoothing: antialiased; }
   .cAlphaShadow(@a, @b, @c, @d, @e) when (@e > 1) { text-shadow: (0px + @a) (0px + @b) (0px + @c) rgba(@d, @d, @d, 1); }
   .cAlphaShadow(@a, @b, @c, @d, @e) when (@e < 1) { text-shadow: (0px + @a) (0px + @b) (0px + @c) rgba(@d, @d, @d, @e); }
   
   @cHighlight: percentage(@cLightness + @cDelta);
   @cLowlight: percentage(@cLightness - @cDelta);
   @cSuperLowLight: percentage(@cLightness - @cDelta * @cMultiplier);