Changes

<p>Patent start Maintenance Fee Schedule:</p><p>https://www.uspto.gov/learning-and-resources/fees-and-payment/uspto-fee-schedule#Patent </p><p>Maintenance fees need to be paid 3.5 ~4, 7.5 ~8, and 11.5 ~12 years after grant</p><p>After some time, t, patents are valid from the grant date to 20 years after the application date.</p><p>Before t, patents are valid from the application date end to 18 years before the grant date project.</p><p><strong>I don&rsquo;t know what happens when people don&rsquo;t pay maintenance fees.</strong></p><p>There is enough information in the <strong>patent </strong>&nbsp;and <strong>feestatus </strong>table to create a <strong>patentStartdateEnddate</strong> table.</p><p>http://mcnair.bakerinstitute.org/wiki/Patent_Table</p><p>http://mcnair.bakerinstitute.org/wiki/Fee_Status_Table</p>

Patent Maintenance Fee Schedulehttps://www.uspto.gov/learning-and-resources/fees-and-payment/uspto-fee-schedule#Patent Maintenance Fee Fees need to be paid 3.5 ~4, 7.5 ~8, and 11.5 ~12 years after grantAfter some time, t, patents are valid from the grant date to 20 years after the application date.Before t, patents are valid from the application date to 18 years before the grant date. '''I don’t know what happens when people don’t pay maintenance fees.''' There is enough information in the patent and feestatus table to create a patentStartdateEnddate table. <p>Table we want to make:</p>  <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Table "public.patentstartdateenddate"</p><p>Column &nbsp; | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Type &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; | Modifiers </p><p>---------+--------------------+-----------</p><p>patent &nbsp; | character varying | </p><p>start &nbsp; &nbsp; &nbsp;| date &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; | </p><p>end &nbsp; &nbsp; &nbsp; | date &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;| </p><p>&nbsp;</p><p><strong>Methodology:</strong></p><p>Take the patentID from the ''patent'' table.</p><p>Check if a fee has been paid within a certain date range using the ''feestatus'' table.</p><p>The date range will have to be determined by learning about the rules around maintenance fees.</p>