The following caption can be found beneath the Heptagon on page eleven of Aleister Crowley’s The Book of Thoth.
The Days of the Week
Read around the Hexagon, the (magical)
Order of the Seven Sacred Planets. Read along
the Hexagram, the order of the days of the
week. (It is believed that this neat discovery
is due to the late G. H. Frater D.D.C.F.)
Frater D.D.C.F. (Deo Duce Comite Ferro) was Samuel Liddell MacGregor Mathers, head of the G∴ D∴ and the R.R. et A.C. when Crowley first met him in 1898 c.e.
And, yes, it does say: Read around the Hexagon and Read along the Hexagram. It should have said Heptagon and Heptagram, seven sided polygon and seven pointed star.