Miss Achelis started a movement promoting adoption of The World Calendar after attending a lecture in 1929 by Dr. Melvyl Dewey (of the "Decimal System") on the necessity of simplfying life.

She became the President of the World Calendar Association at its inception in 1930, and continued to be the lead spokesperson for the adoption of that plan of calendar reform for the rest of her life. The Association was funded by her personal fortune and donations.

Although a regular participant in calendar reform-activities at the League of Nations and the United Nations, Miss Achelis was prevented from lobbying for the U. S. Government's adoption of The World Calendar in order to preserve the tax-exempt status of the Association.

Ten years after the American Affiliate of the Association was disbanded and moved to Ottawa, the 86-year-old Miss Achelis had made progress in Washington by managing to secure "guarded support" of The World Calendar from then House Minority Leader Gerald R. Ford (MI) and Sen. John O. Pastore (RI).

A New York Times article about her on Sept. 26, 1966 included a quaint observation: "More recently, the advent of the computer has added a new incentive to the calendar reformers. Under the Gregorian calendar, computers must be rescheduled with a new program each year. The World Calendar would eliminate this."

In addition to numerous speeches before civil and professional groups, Miss Achelis regularly contributed articles to the Association's Journal of Calendar Reform, and published four books on the calendar:

• The World Calendar (Putnam: New York, 1937)
• The Calendar For Everybody (Putnam: New York, 1943; Omnigraphics: Detroit, 1990)
• Of Time and the Calendar (New York: Hermitage House, 1955)
• The Calendar For the Modern Age (Nelson: New York, 1959)