se/topics/as.Date'>as.Date</a></span>(<span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/c'>c</a></span>(<span class='st'>"2017-01-01"</span>, <span class='st'>"2017-03-01"</span>, <span class='st'>"2017-05-01"</span>,
<span class='st'>"2017-01-01"</span>, <span class='st'>"2017-02-01"</span>, <span class='st'>"2017-04-01"</span>)),
<span class='kw'>id</span> <span class='kw'>=</span> <span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/rep'>rep</a></span>