diff --git a/DESCRIPTION b/DESCRIPTION
index 6331cf4..70bb1ba 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -2,8 +2,9 @@ Package: lubridateExtras
 Type: Package
 Title: Convenience functions for the lubridate package
 Version: 0.1.0
-Authors@R: person("Ellis", "Valentiner", email = "ellis.valentiner@gmail.com",
-                  role = c("aut", "cre"))
+Authors@R: c(
+    person("Ellis", "Valentiner", email = "ellis.valentiner@gmail.com", role = c("aut", "cre")),
+    person("Geoffrey", "Hannigan", email = "hanni035@umn.edu", role = c("ctb")))
 Description: Provides extra functionality to lubridate. Largely consisting of
     convenience functions.
 License: MIT + file LICENSE
@@ -11,6 +12,9 @@ Encoding: UTF-8
 LazyData: true
 Imports:
   lubridate (>= 1.6.0)
+Suggests:
+  knitr
 Remotes:
   tidyverse/lubridate
+VignetteBuilder: knitr
 RoxygenNote: 6.0.1
diff --git a/README.md b/README.md
index e4f9fc4..d5464d4 100644
--- a/README.md
+++ b/README.md
@@ -30,16 +30,16 @@ Usage
 library(lubridateExtras)
 
 yesterday()
-#> [1] "2017-09-23"
+#> [1] "2017-10-11"
 
 tomorrow()
-#> [1] "2017-09-25"
+#> [1] "2017-10-13"
 
 days_ago(7)  # equivalent to lubridate::today() - lubridate::days(7)
-#> [1] "2017-09-17"
+#> [1] "2017-10-05"
 
 days_hence(7)  # equivalent to lubridate::today() + lubridate::days(7)
-#> [1] "2017-10-01"
+#> [1] "2017-10-19"
 ```
 
 Why lubridateExtras?
diff --git a/docs/articles/intro.html b/docs/articles/intro.html
index 6052a03..d22ee69 100644
--- a/docs/articles/intro.html
+++ b/docs/articles/intro.html
@@ -64,10 +64,10 @@ <h1>Introduction to lubridateExtras</h1>
     
     
 <div class="contents">
+<p>lubridateExtras provides functions to improve code readability and increase laziness.</p>
 <div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r"><span class="kw">suppressPackageStartupMessages</span>(<span class="kw">library</span>(dplyr))
 <span class="kw">suppressPackageStartupMessages</span>(<span class="kw">library</span>(lubridate))
 <span class="kw">library</span>(lubridateExtras)</code></pre></div>
-<p>lubridateExtras provides functions to improve code readability and increase laziness.</p>
 <div id="example" class="section level2">
 <h2 class="hasAnchor">
 <a href="#example" class="anchor"></a>Example</h2>
diff --git a/docs/authors.html b/docs/authors.html
index a970d12..01c2c14 100644
--- a/docs/authors.html
+++ b/docs/authors.html
@@ -88,6 +88,10 @@ <h1>Authors</h1>
         <p><strong>Ellis Valentiner</strong>. Author, maintainer.
         </p>
       </li>
+      <li>
+        <p><strong>Geoffrey Hannigan</strong>. Contributor.
+        </p>
+      </li>
     </ul>
 
   </div>
diff --git a/docs/index.html b/docs/index.html
index 217f602..bf0aaf9 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -86,16 +86,16 @@ <h2 class="hasAnchor">
 <div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r"><span class="kw">library</span>(lubridateExtras)
 
 <span class="kw"><a href="reference/yesterday.html">yesterday</a></span>()
-<span class="co">#&gt; [1] "2017-09-23"</span>
+<span class="co">#&gt; [1] "2017-10-11"</span>
 
 <span class="kw"><a href="reference/tomorrow.html">tomorrow</a></span>()
-<span class="co">#&gt; [1] "2017-09-25"</span>
+<span class="co">#&gt; [1] "2017-10-13"</span>
 
 <span class="kw"><a href="reference/days_ago.html">days_ago</a></span>(<span class="dv">7</span>)  <span class="co"># equivalent to lubridate::today() - lubridate::days(7)</span>
-<span class="co">#&gt; [1] "2017-09-17"</span>
+<span class="co">#&gt; [1] "2017-10-05"</span>
 
 <span class="kw"><a href="reference/days_hence.html">days_hence</a></span>(<span class="dv">7</span>)  <span class="co"># equivalent to lubridate::today() + lubridate::days(7)</span>
-<span class="co">#&gt; [1] "2017-10-01"</span></code></pre></div>
+<span class="co">#&gt; [1] "2017-10-19"</span></code></pre></div>
 </div>
 <div id="why-lubridateextras" class="section level2">
 <h2 class="hasAnchor">
@@ -114,6 +114,7 @@ <h2 class="hasAnchor">
 <h2>Developers</h2>
 <ul class="list-unstyled">
 <li>Ellis Valentiner <br><small class="roles"> Author, maintainer </small> </li>
+<li><a href="authors.html">All authors...</a></li>
 </ul>
 </div>
 
diff --git a/docs/reference/days_ago.html b/docs/reference/days_ago.html
index d3fce2a..b348584 100644
--- a/docs/reference/days_ago.html
+++ b/docs/reference/days_ago.html
@@ -110,7 +110,7 @@ <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>
     
 
     <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
-    <pre class="examples"><div class='input'><span class='fu'>days_ago</span>(<span class='fl'>3</span>)</div><div class='output co'>#&gt; [1] "2017-09-21"</div><div class='input'><span class='fu'>days_ago</span>(<span class='fl'>1</span>) <span class='kw'>==</span> <span class='fu'><a href='yesterday.html'>yesterday</a></span>()</div><div class='output co'>#&gt; [1] TRUE</div></pre>
+    <pre class="examples"><div class='input'><span class='fu'>days_ago</span>(<span class='fl'>3</span>)</div><div class='output co'>#&gt; [1] "2017-10-09"</div><div class='input'><span class='fu'>days_ago</span>(<span class='fl'>1</span>) <span class='kw'>==</span> <span class='fu'><a href='yesterday.html'>yesterday</a></span>()</div><div class='output co'>#&gt; [1] TRUE</div></pre>
   </div>
   <div class="col-md-3 hidden-xs hidden-sm" id="sidebar">
     <h2>Contents</h2>
diff --git a/docs/reference/days_hence.html b/docs/reference/days_hence.html
index 22deeca..3787f60 100644
--- a/docs/reference/days_hence.html
+++ b/docs/reference/days_hence.html
@@ -110,7 +110,7 @@ <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>
     
 
     <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
-    <pre class="examples"><div class='input'><span class='fu'>days_hence</span>(<span class='fl'>3</span>)</div><div class='output co'>#&gt; [1] "2017-09-27"</div><div class='input'><span class='fu'>days_hence</span>(<span class='fl'>1</span>) <span class='kw'>==</span> <span class='fu'><a href='tomorrow.html'>tomorrow</a></span>()</div><div class='output co'>#&gt; [1] TRUE</div></pre>
+    <pre class="examples"><div class='input'><span class='fu'>days_hence</span>(<span class='fl'>3</span>)</div><div class='output co'>#&gt; [1] "2017-10-15"</div><div class='input'><span class='fu'>days_hence</span>(<span class='fl'>1</span>) <span class='kw'>==</span> <span class='fu'><a href='tomorrow.html'>tomorrow</a></span>()</div><div class='output co'>#&gt; [1] TRUE</div></pre>
   </div>
   <div class="col-md-3 hidden-xs hidden-sm" id="sidebar">
     <h2>Contents</h2>
diff --git a/docs/reference/tomorrow.html b/docs/reference/tomorrow.html
index 9ce5a8f..c9b41c3 100644
--- a/docs/reference/tomorrow.html
+++ b/docs/reference/tomorrow.html
@@ -106,7 +106,7 @@ <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>
     
 
     <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
-    <pre class="examples"><div class='input'><span class='fu'>tomorrow</span>()</div><div class='output co'>#&gt; [1] "2017-09-25"</div><div class='input'><span class='fu'>tomorrow</span>(<span class='st'>"GMT"</span>)</div><div class='output co'>#&gt; [1] "2017-09-26"</div></pre>
+    <pre class="examples"><div class='input'><span class='fu'>tomorrow</span>()</div><div class='output co'>#&gt; [1] "2017-10-13"</div><div class='input'><span class='fu'>tomorrow</span>(<span class='st'>"GMT"</span>)</div><div class='output co'>#&gt; [1] "2017-10-13"</div></pre>
   </div>
   <div class="col-md-3 hidden-xs hidden-sm" id="sidebar">
     <h2>Contents</h2>
diff --git a/docs/reference/yesterday.html b/docs/reference/yesterday.html
index ff493d9..5924c7b 100644
--- a/docs/reference/yesterday.html
+++ b/docs/reference/yesterday.html
@@ -106,7 +106,7 @@ <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>
     
 
     <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
-    <pre class="examples"><div class='input'><span class='fu'>yesterday</span>()</div><div class='output co'>#&gt; [1] "2017-09-23"</div><div class='input'><span class='fu'>yesterday</span>(<span class='st'>"GMT"</span>)</div><div class='output co'>#&gt; [1] "2017-09-24"</div></pre>
+    <pre class="examples"><div class='input'><span class='fu'>yesterday</span>()</div><div class='output co'>#&gt; [1] "2017-10-11"</div><div class='input'><span class='fu'>yesterday</span>(<span class='st'>"GMT"</span>)</div><div class='output co'>#&gt; [1] "2017-10-11"</div></pre>
   </div>
   <div class="col-md-3 hidden-xs hidden-sm" id="sidebar">
     <h2>Contents</h2>
diff --git a/lubridateExtras.Rproj b/lubridateExtras.Rproj
index b512aa3..fb8028e 100644
--- a/lubridateExtras.Rproj
+++ b/lubridateExtras.Rproj
@@ -17,4 +17,4 @@ StripTrailingWhitespace: Yes
 BuildType: Package
 PackageUseDevtools: Yes
 PackageInstallArgs: --no-multiarch --with-keep.source
-PackageRoxygenize: rd,collate,namespace
+PackageRoxygenize: rd,collate,namespace,vignette
diff --git a/vignettes/intro.Rmd b/vignettes/intro.Rmd
index cea43bb..af45b21 100644
--- a/vignettes/intro.Rmd
+++ b/vignettes/intro.Rmd
@@ -1,18 +1,20 @@
 ---
 title: "Introduction to lubridateExtras"
-output: html_document
-editor_options: 
-  chunk_output_type: console
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{Introduction to lubridateExtras}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
 ---
 
-```{r}
+lubridateExtras provides functions to improve code readability and increase laziness.
+
+```{r, eval=FALSE}
 suppressPackageStartupMessages(library(dplyr))
 suppressPackageStartupMessages(library(lubridate))
 library(lubridateExtras)
 ```
 
-lubridateExtras provides functions to improve code readability and increase laziness.
-
 ## Example
 
 Suppose you want to review transactions from the past 7 days.