Through its books, the Magi Society advocates the use of declinations, heliocentric longitudes and latitudes in astrology as well as offering a methodology to interpret them.
2.
Lowell's system was not a true calendar, since a Mars date could span nearly two entire sols; rather it was a convenient device for expressing the time of year in the southern hemisphere in lieu of heliocentric longitude, which would have been less comprehensible to a general readership.