diff --git a/R/derive_date_vars.R b/R/derive_date_vars.R
index 1c65d29c44..b2ef501255 100644
--- a/R/derive_date_vars.R
+++ b/R/derive_date_vars.R
@@ -101,7 +101,9 @@
 #' `"23:59:59"`. Specifying date variables makes sense only if the date is
 #' imputed. If only time is imputed, date variables do not affect the result.
 
-#' @param preserve Preserve day if month is missing and day is present
+#' @param preserve Preserve lower level date/time part when higher order part
+#' is missing, e.g. preserve day if month is missing or
+#' preserve minute when hour is missing.
 #'
 #' For example `"2019---07"` would return `"2019-06-07` if `preserve = TRUE`
 #' (and `date_imputation = "mid"`).
diff --git a/man/convert_date_to_dtm.Rd b/man/convert_date_to_dtm.Rd
index d15849dade..1fc0e944e1 100644
--- a/man/convert_date_to_dtm.Rd
+++ b/man/convert_date_to_dtm.Rd
@@ -113,7 +113,9 @@ For date variables (not datetime) in the list the time is imputed to
 \code{"23:59:59"}. Specifying date variables makes sense only if the date is
 imputed. If only time is imputed, date variables do not affect the result.}
 
-\item{preserve}{Preserve day if month is missing and day is present
+\item{preserve}{Preserve lower level date/time part when higher order part
+is missing, e.g. preserve day if month is missing or
+preserve minute when hour is missing.
 
 For example \code{"2019---07"} would return \verb{"2019-06-07} if \code{preserve = TRUE}
 (and \code{date_imputation = "mid"}).
diff --git a/man/convert_dtc_to_dtm.Rd b/man/convert_dtc_to_dtm.Rd
index 3d612f2092..3892f5e340 100644
--- a/man/convert_dtc_to_dtm.Rd
+++ b/man/convert_dtc_to_dtm.Rd
@@ -111,7 +111,9 @@ For date variables (not datetime) in the list the time is imputed to
 \code{"23:59:59"}. Specifying date variables makes sense only if the date is
 imputed. If only time is imputed, date variables do not affect the result.}
 
-\item{preserve}{Preserve day if month is missing and day is present
+\item{preserve}{Preserve lower level date/time part when higher order part
+is missing, e.g. preserve day if month is missing or
+preserve minute when hour is missing.
 
 For example \code{"2019---07"} would return \verb{"2019-06-07} if \code{preserve = TRUE}
 (and \code{date_imputation = "mid"}).
diff --git a/man/derive_vars_dtm.Rd b/man/derive_vars_dtm.Rd
index f8bbd4f8c0..9ae460f7a0 100644
--- a/man/derive_vars_dtm.Rd
+++ b/man/derive_vars_dtm.Rd
@@ -140,7 +140,9 @@ For date variables (not datetime) in the list the time is imputed to
 \code{"23:59:59"}. Specifying date variables makes sense only if the date is
 imputed. If only time is imputed, date variables do not affect the result.}
 
-\item{preserve}{Preserve day if month is missing and day is present
+\item{preserve}{Preserve lower level date/time part when higher order part
+is missing, e.g. preserve day if month is missing or
+preserve minute when hour is missing.
 
 For example \code{"2019---07"} would return \verb{"2019-06-07} if \code{preserve = TRUE}
 (and \code{date_imputation = "mid"}).
diff --git a/man/impute_dtc_dtm.Rd b/man/impute_dtc_dtm.Rd
index 8e0f8c0e8c..8abafde845 100644
--- a/man/impute_dtc_dtm.Rd
+++ b/man/impute_dtc_dtm.Rd
@@ -115,7 +115,9 @@ For date variables (not datetime) in the list the time is imputed to
 \code{"23:59:59"}. Specifying date variables makes sense only if the date is
 imputed. If only time is imputed, date variables do not affect the result.}
 
-\item{preserve}{Preserve day if month is missing and day is present
+\item{preserve}{Preserve lower level date/time part when higher order part
+is missing, e.g. preserve day if month is missing or
+preserve minute when hour is missing.
 
 For example \code{"2019---07"} would return \verb{"2019-06-07} if \code{preserve = TRUE}
 (and \code{date_imputation = "mid"}).