For the years 2001-2008 , we use full-disk , SOHO/EIT 195 \AA calibrated images to determine latitudinal and day to day variations of the rotation rates of coronal holes .
We estimate the weighted average of heliographic coordinates such as latitude and longitude from the central meridian on the observed solar disk .
For different latitude zones between 40 ^ { o } north - 40 ^ { o } south , we compute rotation rates , and find that , irrespective of their area , number of days observed on the solar disk and latitudes , coronal holes rotate rigidly .
Combined for all the latitude zones , we also find that coronal holes rotate rigidly during their evolution history .
In addition , for all latitude zones , coronal holes follow a rigid body rotation law during their first appearance .
Interestingly , average first rotation rate ( \sim 438 nHz ) of the coronal holes , computed from their first appearance on the solar disk , match with rotation rate of the solar interior only below the tachocline .