Comparability
BIRTHMO_ET (V009) has no comparability problems across Ethiopian samples.
All standard date variables in Ethiopia DHS samples are given in the Ethiopian calendar. The Ethiopian year consists of 365 days, divided into 12 months of 30 days and one month of 5 days (6 days in a leap year). According to the Gregorian calendar, the Ethiopian year begins September 11 and ends the following September 10. The 13th month of the Ethiopian calendar falls in September. It is only possible to convert dates given in the Ethiopian calendar to the Gregorian calendar when the exact date (day, month and year) is available. Otherwise, it is only possible to approximate to the month. In general, the Ethiopian calendar is 92 months behind the Gregorian calendar.
Although there are thirteen months in the Ethiopian calendar, BIRTHMO_ET (V009) contains only values 1 to 12. Presumably, women born in the thirteenth month are given code 12.
Comparability - Standard DHS
BIRTHMO_ET (V009) is included in every phase of the standard DHS questionnaire for Ethiopia.
