Comparability
PRECALTERMMO_ET (V240_ET) varies slightly across Ethiopian samples in how days and months are recorded.
All standard date variables in the Ethiopian 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, in a non-leap year, the Ethiopian year begins September 11 and ends the following September 10. The 13th month of the Ethiopian calendar falls in early September. In general, the Ethiopian calendar is 92 months behind the Gregorian calendar.
In the 2000 and 2005 Ethiopia samples, all date variables use the Ethiopian calendar, exactly as described above.
In the 2011 and 2016 Ethiopia samples, the date variables use the Ethiopian calendar as a starting point, but some recoding has been done to make the Ethiopian data resemble the 12 month units of the Gregorian calendar. For example, the month of January (month 1) in the Gregorian calendar has 31 days, while the month of Meskerem (month 1) in the Ethiopian calendar has only 30 days. In the conversion process, the first day of Tikimt (month 2) is recoded as the 31st day of month 1. Month 2 in the conversion will have 28 or 29 days (as the Gregorian calendar's February has), depending on whether the year in question is a leap year according to the Gregorian calendar. By doing this conversion, The DHS Program distributes the 365 days of the Ethiopian year into just 12 months, allowing DHS to apply the same procedures used in surveys for other countries.
Comparability - Standard DHS
PRECALTERMMO_ET (V240_ET) is included in Phase IV forward of the standard DHS questionnaire for Ethiopian samples.
