|
|
|
|
|
|
|
at the end of the year, and you have decided that the last year of the mard should contain the exceptional days. |
|
|
|
|
|
|
|
|
Thus, in a leap year, the year has (3167 + 168 =) 669 days, as required. |
|
|
|
|
|
|
|
|
It is reasonable to inquire into the possibility of arranging the month lengths in a way that would reflect the relative lengths of the seasons. The Persian Solar calendar does this, for example, by assigning slightly longer lengths to the first six months of the year, in order to adjust the relative lengths of summer and winter. This scheme attempts to coerce certain calendar dates to coincide with solstices and equinoces. |
|
|
|
|
|
|
|
|
Using the seasonal lengths from Table 9.36 and retaining the concept of quarters and 12 Martian months in one Martian year, one could create Table 9.38. |
|
|
|
|
|
|
|
|
There is one major difficulty with this idea. The Persian Solar calendar assumes that the current relationship between summer and winter lengths is constant. Like most assumptions regarding the fixity of calendric values, this assumption is false. The relationship between perihelion and season is variable. Around 4080 B.C., for example, Earth was in perihelion at the start of autumn. By A.D. 1246, Earth was in perihelion at the time of the winter solstice. The eccentricity of Earth's orbit is a contributing factor to this variation. It would be pointless to twist the Martian year into conformity with a particular set of seasonal ratios when these ratios are in a state of constant flux. The greater eccentricity of the Martian orbit means that this argument applies with even greater force in the case of Mars. |
|
|
|
|
| Table 9.38 Martian months that reflect the relative lengths of the seasons. | | Northern Season | Total Days | | Days in Month 1 | | Days in Month 2 | | Days in Month 3 | | Spring | 194 | | | | | | | | Summer | 176 | | | | | | | | Autumn | 142 | | | | | | | | Winter | 156 | | | | | | |
|
|
|