diff --git a/hledger-lib/Hledger/Data/AutoTransaction.hs b/hledger-lib/Hledger/Data/AutoTransaction.hs
index 4cc903005..87d5de4e1 100644
--- a/hledger-lib/Hledger/Data/AutoTransaction.hs
+++ b/hledger-lib/Hledger/Data/AutoTransaction.hs
@@ -147,7 +147,69 @@ renderPostingCommentDates p = p { pcomment = comment' }
 -- 2017/03/01
 --     hi           $1.00
 -- <BLANKLINE>
--- >>> gen "every Nov 29th from 2017 to 2019"
+-- >>> gen "monthly from 2017/1 to 2017/5"
+-- 2017/01/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/02/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/03/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/04/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- >>> gen "every 2nd day of month from 2017/02 to 2017/04"
+-- 2017/01/02
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/02/02
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/03/02
+--     hi           $1.00
+-- <BLANKLINE>
+-- >>> gen "monthly from 2017/1 to 2017/4"
+-- 2017/01/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/02/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/03/01
+--     hi           $1.00
+-- <BLANKLINE>
+-- >>> gen "every 30th day of month from 2017/1 to 2017/5"
+-- 2016/12/30
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/01/30
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/02/28
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/03/30
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/04/30
+--     hi           $1.00
+-- <BLANKLINE>
+-- >>> gen "every 2nd Thursday of month from 2017/1 to 2017/4"
+-- 2016/12/08
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/01/12
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/02/09
+--     hi           $1.00
+-- <BLANKLINE>
+-- 2017/03/09
+--     hi           $1.00
+-- <BLANKLINE>
+-- >>> gen "every nov 29th from 2017 to 2019"
 -- 2016/11/29
 --     hi           $1.00
 -- <BLANKLINE>
diff --git a/hledger-lib/Hledger/Data/Dates.hs b/hledger-lib/Hledger/Data/Dates.hs
index 8e6c29d19..14500963a 100644
--- a/hledger-lib/Hledger/Data/Dates.hs
+++ b/hledger-lib/Hledger/Data/Dates.hs
@@ -184,7 +184,7 @@ splitSpan (Weeks n)      s = splitspan startofweek    (applyN n nextweek)    s
 splitSpan (Months n)     s = splitspan startofmonth   (applyN n nextmonth)   s
 splitSpan (Quarters n)   s = splitspan startofquarter (applyN n nextquarter) s
 splitSpan (Years n)      s = splitspan startofyear    (applyN n nextyear)    s
-splitSpan (DayOfMonth n) s = splitspan (nthdayofmonthcontaining n) (applyN (n-1) nextday . nextmonth) s
+splitSpan (DayOfMonth n) s = splitspan (nthdayofmonthcontaining n) (nthdayofmonth n . nextmonth) s
 splitSpan (WeekdayOfMonth n wd) s = splitspan (nthweekdayofmonthcontaining n wd) (advancetonthweekday n wd . nextmonth) s
 splitSpan (DayOfWeek n)  s = splitspan (nthdayofweekcontaining n)  (applyN (n-1) nextday . nextweek)  s
 splitSpan (DayOfYear m n) s= splitspan (nthdayofyearcontaining m n) (applyN (n-1) nextday . applyN (m-1) nextmonth . nextyear) s
@@ -456,6 +456,7 @@ thismonth = startofmonth
 prevmonth = startofmonth . addGregorianMonthsClip (-1)
 nextmonth = startofmonth . addGregorianMonthsClip 1
 startofmonth day = fromGregorian y m 1 where (y,m,_) = toGregorian day
+nthdayofmonth d day = fromGregorian y m d where (y,m,_) = toGregorian day
 
 thisquarter = startofquarter
 prevquarter = startofquarter . addGregorianMonthsClip (-3)
@@ -514,8 +515,8 @@ nthdayofyearcontaining m n d | mmddOfSameYear <= d = mmddOfSameYear
 -- 2017-10-30          
 nthdayofmonthcontaining n d | nthOfSameMonth <= d = nthOfSameMonth
                             | otherwise = nthOfPrevMonth
-    where nthOfSameMonth = addDays (fromIntegral n-1) s
-          nthOfPrevMonth = addDays (fromIntegral n-1) $ prevmonth s
+    where nthOfSameMonth = nthdayofmonth n s
+          nthOfPrevMonth = nthdayofmonth n $ prevmonth s
           s = startofmonth d
 
 -- | For given date d find week-long interval that starts on nth day of week