How can I use Spatial Indexes for timestamps (non-spatial 1d data)?
TIMESTAMP, DATETIME, INT, FLOAT, DECIMAL, etc are effectively "numbers".  Numbers can be ordered/searched/etc with ordinary BTREE indexes.  There is no need for SPATIAL for such one-dimensional quantities.

For date-like quantities, I like to do:

WHERE ts &gt;= '2018-02-23'
  AND ts  &lt; '2018-02-23' + INTERVAL 3 WEEK

INDEX(ts)


This avoids dealing with leap years, kludges like '23:59:59', inclusive/exclusive (not the careful choice of inequality operators), etc.