Fertility calculator

Claim 1

A DISCOIDAL DEVICE FOR CALCULATING THE LENGTH AND STARTING DATE OF THE FERTILE DAYS OF A WOMAN COMPRISING A LEAST THREE CONCENTRIC DISCS, A FIRST OF WHICH IS FIXED; SECOND AND THRID OF SAID DISCS BEING SELECTIVELY ROTATABLE WITH RESPECT TO SAID FIRST DISC; SAID FIRST DISC BEING ANNULAR AND OVERLYING SAID SECOND AND THIRD DISCS AND HAVING A FIRST SET OF NUMERALS FOR DESIGNATING THE DATE OF THE START OF THE WOMAN''S LAST MENSTRUAL CYCLE ABOUT THE INNER PERIPHERY OF A FACE THEREOF; SAID SECOND DISC HAVING A SECOND ARCUATE SET OF NUMERALS COVERED BY SAID FIRST DISC FOR DESIGNATING THE LENGTH IN DAYS OF THE SHORTEST MENSTRUAL CYCLE OF SAID WOMAN IN A PREVIOUS PRESELECTED PERIOD OF TIME; SAID FIRST DISC HAVING A WINDOW OVERLYING SAID SECOND SET OF NUMERALS TO DISPLAY SELECTIVELY NUMERALS FROM SAID SECOND SET; AND A THIRD SET OF NUMERALS ON SAID SECOND DISC INWARDLY OF SAID FIRST DISC FOR DESIGNATING THE DAYS OF THE MONTHS HAVING 30 AND 31 DAYS; SAID THIRD SET OF NUMERALS BEING IN A PREDETERMINED RELATIONSHIP TO SAID SECOND SET OF NUMERALS SO THAT WHEN A NUMERAL FROM SAID SECOND SET IS DISPLAYED IN SAID WINDOW ON SAID FIRST DISC THE NUMERALS OF SAID THIRD SET ARE RADIALLY ALIGNED WITHE NUMERALS OF SAID FIRST SET TO PROVIDE THE STARTING DATES OF THE FERTILE DAYS OF THE WOMAN CORRESPONDING TO SUCH NUMERAL IN SID WINDOW AND THE RESPECTIVE NUMERALS OF SAID FIRST SET; A FOURTH SET OF ARCUATE NUMERALS ON SAID THIRD DISC FOR DESIGNATING THE VARIANCE IN DAYS OF THE WOMAN''S LONGEST AND SHORTEST MENSTRUAL CYCLES DURING A PRESELECTED PERIOD OF TIME; AND A FIFTH SET OF ARCUATE NUMERALS ON SAID THIRD DISC, EACH NUMERAL OF WHICH HAS A PREDETERMINED RELATIONSHIP TO A NUMERAL IN SAID FOURTH SET AND HAS A VALUE IN DAYS FIVE GREATER THAN SUCH NUMERAL OF SAID FOURTH SET; SAID FIRST DISC HAVING A PAIR OF WINDOWS, THE FIRST WINDOW OVERLIES SAID FOURTH SET OF NUMERALS TO DISPLAY SELECTIVELY NUMERALS FROM SAID FOURTH SET OF NUMERALS TO DISPLAY SELECTIVELY OVERLIES SAID FIFTH SET OF NUMERALS IN SUCH ABOVE-MENTIONED PREDETERMINED RELATIONSHIP, WHEREBY WHEN ANY ONE OF THE NUMERALS FROM SAID FOURTH SET OF NUMERALS IS DISPLAYED IN THE FIRST OF SAID PAIR OF WINDOWS SAID NUMERAL FROM SAID FIFTH SET OF A VALUE FIVE GREATER THAN SUCH NUMERAL FROM SAID FOURTH SET IS DIAPLAYED IN SAID SECOND WINDOW.