Demographic and Health Surveys Methodology - Measure DHS

Century Month Code (CMC)Century month codes (CMC) are calculated by multiplying by 12 the difference between the year of anevent and 1900. That year was chosen as the reference period because all of the DHS relevant eventsoccurred during the twentieth or twenty-first centuries. The month of the event is added to the previousresult.CMC = (Year–1900 ) * 12 + MonthFor example, the CMC for June 2002 will be:CMC = (2002–1900) * 12 + 6 = 1230In other words, 1,230 months have elapsedsince January 1900 to June 2002. Based on CMC it is possible to calculate the month andyear using the following formulas:Year = int( ( CMC – 1 )/12 ) + 1900 [int(x) is the integer part of x]Month = CMC – ( ( Year – 1900 ) * 12 )Century month codes are particularly important to check consistency of dates, to calculate intervalsbetween events, and to impute dates when the information for an event is missing or partially complete.The main DHS events, along with their corresponding recode variable numbers in the recode file, are thefollowing:• Respondent’s date of birth (DOB, V011)• Date of first union (DOM, V509)• Date of birth for each of the respondent’s children ( DBCx, B3(1), B3(2), … B3(n) )• Date of current pregnancy (DOP, V214)• Date of sterilization (DOS, V317)• Date of interview (DOI, V008).Where appropriate, the DHS file also includes variables for the month and year in which the eventsoccurred. For example, V009 and V010 are the woman’s month and year of birth. If an event was notexperienced by the respondent, variables for that event will not exist or will be not applicable.Example:Let us see the events for a married, sterilized respondent with three births and with event dates thatoccurred as shown in the following figure. If a horizontal line is drawn from the woman’s date of birth tothe date of interview, all the events can be depicted in the line.VARS V011 V509 B3(1) B3(2) B3(3) V317 V008DATES 04/79 10/97 07/98 10/99 11/00 04/01 08/01CMC 952 1174 1183 1198 1211 1216 1220EVENTS DOB DOM DBC1 DBC2 DBC3 DOS DOIGuide to DHS Statistics 15 September 2003