A New Year

At dusk yesterday, or today as we know it can also be, depending on which system we are using, the first day of a new year according to lunar-based Islamic calendar began. We are now in the year 1429H. The lunar calendar is based on the cycles of the moon. It divides a year into 12 months with either 29 or 30 days to a month. The Gregorian solar calendar, which is widely used now, also has 12 months to a year but the number of days in a month varies from 28 to 31 days.
Those who were born on 29 February can rejoice this year and look forward to receive birthday presents; good friends may even present gifts of 3-year equivalent. Alternatively, find the corresponding date of birth on the lunar calendar and announce to friends annually of the birthday, whatever date that may be on the solar calendar. The setback is that you get older faster, but think of the gifts, which can be twice a year.
The lunar calendar is shorter than the Gregorian calendar by about 11-13 days; and it is not linked to seasons of the year. Thus every other 33-34 years the lunar and Gregorian calendars meet. Such meeting almost take place this year as the next new year's day for the lunar calendar is on 27 December. Imagine two points, one each at the circumference of two wheels of same diameter but rotate at different speeds. Depending on the speeds of rotation, there would be time when both points meet.
On the eighth month the lunar calendar is 'calibrated' against the phase of the moon to determine the beginning of the ninth month, Ramadhan, which is the fasting month. On the 28th day of Ramadhan again the moon phase is observed to determine the end of fasting and the beginning of the tenth month, Syawal. Thus the calendar gets calibrated twice every year. Nowadays, calculations are also widely used for that determination.