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Child birthday in century month (sixth-youngest child)

KID6DOBCMC is a 4-digit variable that represents the century-month value (months since 1900) for the birthdate of the woman's sixth-youngest child. The following values represent NIU (not in universe) or missing cases:

9995 = Not interviewed (female questionnaire)
9996 = Not interviewed (household questionnaire)
9999 = NIU (not in universe)


For women who are primary caregivers for at least six children in the household under age 5, KID6DOBCMC reports the century month code (CMC) for the date of their sixth-youngest child's birth.

Note that due to the data entry format of the survey, if a respondent reported a year but not a month for the birthdate of the woman's sixth-youngest child, January was the default month.

Enumerators were instructed to enter the date as January 1st, 2020 if the respondent did not give a response to the associated survey question. IPUMS-PMA has recoded these cases to "No response or missing."

Century month codes (CMC) are particularly useful for checking the consistency of dates, calculating intervals between events, and imputing dates when the information for an event is missing or partially complete.

Century month codes (CMC) are calculated by multiplying by 12 the difference between the year of an event and 1900. The year 1900 was chosen as the reference period because all of the relevant events occurred for PMA2020 during the twentieth or twenty-first centuries. The month of the event is added to the previous result.

CMC = (Year - 1900) * 12 + Month
For example, the CMC for June 2002 is:

CMC = (2002 - 1900) * 12 + 6 = 1230

In other words, 1,230 months have elapsed between January 1900 and June 2002. Starting with CMC figures, one can calculate the month and year using the following formulas:

Year = int( ( CMC - 1 )/12 ) + 1900

[int(x) is the integer part of x]

Month = CMC - ( ( Year - 1900 ) * 12 )

The information above is based on "Online Guide to DHS Statistics" (Rutstein and Rojas, 2006).

The question associated with this variable was included in the female questionnaire.


There are no comparability issues.


  • Women age 15-49 who are the primary caregivers for at least 6 children under age 5.


  • Congo (Democratic Republic): 2015
  • Ghana: 2014
  • Kenya: 2015