diff --git a/NEWS b/NEWS
index d9a8030a3..66099f6ef 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,17 @@ For full details, see the git log at: https://github.com/ksh93/ksh
 
 Any uppercase BUG_* names are modernish shell bug IDs.
 
+2020-07-07:
+
+- Four of the date formats accepted by 'printf %()T' have had their
+  functionality altered to the common behavior of date(1):
+  - '%k' and '%l' print the current hour with blank padding, the former
+    based on a 24-hour clock and the latter a twelve hour clock. These
+    are common extensions present on Linux and *BSD.
+  - '%l' prints the current hour (0-12) with blank padding (GNU and BSD).
+  - '%f' prints a date with the format string '%Y.%m.%d-%H:%M:%S' (BusyBox).
+  - '%q' prints the quarter of the year (GNU).
+
 2020-07-06:
 
 - 'notty' is now written to the ksh auditing file instead of '(null)' if
diff --git a/src/cmd/ksh93/data/builtins.c b/src/cmd/ksh93/data/builtins.c
index b06054e53..0eed506b2 100644
--- a/src/cmd/ksh93/data/builtins.c
+++ b/src/cmd/ksh93/data/builtins.c
@@ -1221,8 +1221,74 @@ USAGE_LICENSE
 		"convert it to an extended regular expression.]"
 	"[+%T?Treat \astring\a as a date/time string and format it.  The "
 		"\bT\b can be preceded by \b(\b\adformat\a\b)\b, where "
-		"\adformat\a is a date format as defined by the \bdate\b "
-		"command.]"
+		"\adformat\a is a date format. The accepted date formats are "
+		"as follows:]{"
+			"[+%?% character]"
+			"[+a?abbreviated weekday name]"
+			"[+A?full weekday name]"
+			"[+b?abbreviated month name]"
+			"[+B?full month name]"
+			"[+c?\bctime\b(3) style date without the trailing newline]"
+			"[+C?2-digit century]"
+			"[+d?day of month number]"
+			"[+D?date as \amm/dd/yy\a]"
+			"[+e?blank padded day of month number]"
+			"[+f?print a date with the format '\%Y.\%m.\%d-\%H:\%M:\%S']"
+			"[+F?%ISO 8601:2000 standard date format; equivalent to Y-%m-%d]"
+			"[+g?\bls\b(1) \b-l\b recent date with \ahh:mm\a]"
+			"[+G?\bls\b(1) \b-l\b distant date with \ayyyy\a]"
+			"[+h?abbreviated month name]"
+			"[+H?24-hour clock hour, zero-padded]"
+			"[+i?international \bdate\b(1) date with time zone type name]"
+			"[+I?12-hour clock hour, zero-padded]"
+			"[+j?1-offset Julian date]"
+			"[+J?0-offset Julian date]"
+			"[+k?24-hour clock hour, blank-padded]"
+			"[+K?all numeric date; equivalent to \b%Y-%m-%d+%H:%M:%S\b; \b%_[EO]]K\b for space separator, %OK adds \b.%N\b, \b%EK\b adds \b%.N%z\b, \b%_EK\b adds \b.%N %z\b]"
+			"[+l?12-hour clock hour, blank-padded]"
+			"[+L?locale default date format]"
+			"[+m?month number]"
+			"[+M?minutes]"
+			"[+n?newline character]"
+			"[+N?nanoseconds 000000000-999999999]"
+			"[+p?meridian (e.g., \bAM\b or \bPM\b)]"
+			"[+q?quarter of the year]"
+			"[+Q?\a<del>recent<del>distant<del>\a: \a<del>\a is a unique "
+				"delimter character; \arecent\a format for recent "
+				"dates, \adistant\a format otherwise]"
+			"[+r?12-hour time as \ahh:mm:ss meridian\a]"
+			"[+R?24-hour time as \ahh:mm\a]"
+			"[+s?number of seconds since the epoch; \a.prec\a preceding "
+				"\bs\b appends \aprec\a nanosecond digits, \b9\b if "
+				"\aprec\a is omitted]"
+			"[+S?seconds 00-60]"
+			"[+t?tab character]"
+			"[+T?24-hour time as \ahh:mm:ss\a]"
+			"[+u?weekday number 1(Monday)-7]"
+			"[+U?week number with Sunday as the first day]"
+			"[+V?ISO week number (i18n is \afun\a)]"
+			"[+w?weekday number 0(Sunday)-6]"
+			"[+W?week number with Monday as the first day]"
+			"[+x?locale date style that includes month, day and year]"
+			"[+X?locale time style that includes hours and minutes]"
+			"[+y?2-digit year (you'll be sorry)]"
+			"[+Y?4-digit year]"
+			"[+z?time zone \aSHHMM\a west of GMT offset where S is "
+				"\b+\b or \b-\b, use pad _ for \aSHH:MM\a]"
+			"[+Z?time zone name]"
+			"[+=[=]][-+]]flag?set (default or +) or clear (-) \aflag\a "
+				"for the remainder of \aformat\a, or for the remainder "
+				"of the process if \b==\b is specified. \aflag\a may be:]{"
+				"[+l?enable leap second adjustments]"
+				"[+n?convert \b%S\b as \b%S.%N\b]"
+				"[+u?UTC time zone]"
+			"}"
+			"[+#?equivalent to %s]"
+			"[+??alternate?use \aalternate\a format if a default format "
+				"override has not been specified, e.g., \bls\b(1) uses "
+				"\"%?%l\"; export TM_OPTIONS=\"format='\aoverride\a'\" "
+				"to override the default]"
+		"}"
 	"[+%Z?Output a byte whose value is \b0\b.]"
 	"\fextra\f"
 "}"
diff --git a/src/cmd/ksh93/include/version.h b/src/cmd/ksh93/include/version.h
index 575941029..394dc9257 100644
--- a/src/cmd/ksh93/include/version.h
+++ b/src/cmd/ksh93/include/version.h
@@ -17,4 +17,4 @@
 *                  David Korn <dgk@research.att.com>                   *
 *                                                                      *
 ***********************************************************************/
-#define SH_RELEASE	"93u+m 2020-07-06"
+#define SH_RELEASE	"93u+m 2020-07-07"
diff --git a/src/cmd/ksh93/sh.1 b/src/cmd/ksh93/sh.1
index 6bfaf96a7..38ba1b5d4 100644
--- a/src/cmd/ksh93/sh.1
+++ b/src/cmd/ksh93/sh.1
@@ -6527,10 +6527,7 @@ A
 .BI %( date-format )T
 format can be used to treat an argument as a date/time string
 and to format the date/time according to the
-.I date-format\^
-as defined for the
-.BR date (1)
-command.
+.IR date-format .
 .TP
 .B %Z
 A
diff --git a/src/cmd/ksh93/tests/builtins.sh b/src/cmd/ksh93/tests/builtins.sh
index fd093c66b..66d465e0a 100755
--- a/src/cmd/ksh93/tests/builtins.sh
+++ b/src/cmd/ksh93/tests/builtins.sh
@@ -749,5 +749,12 @@ unset foo
 	test_func
 )
 
+# ======
+# Test the output of nonstandard date formats with 'printf %T'
+[[ $(printf '%(%l)T') == $(printf '%(%_I)T') ]] || err_exit 'date format %l is not the same as %_I'
+[[ $(printf '%(%k)T') == $(printf '%(%_H)T') ]] || err_exit 'date format %k is not the same as %_H'
+[[ $(printf '%(%f)T') == $(printf '%(%Y.%m.%d-%H:%M:%S)T') ]] || err_exit 'date format %f is not the same as %Y.%m.%d-%H:%M:%S'
+[[ $(printf '%(%q)T') == $(printf '%(%Qz)T') ]] && err_exit 'date format %q is the same as %Qz'
+
 # ======
 exit $((Errors<125?Errors:125))
diff --git a/src/lib/libast/tm/tmxfmt.c b/src/lib/libast/tm/tmxfmt.c
index 2010c0804..bc642ad4e 100644
--- a/src/lib/libast/tm/tmxfmt.c
+++ b/src/lib/libast/tm/tmxfmt.c
@@ -271,8 +271,8 @@ tmxfmt(char* buf, size_t len, const char* format, Time_t t)
 		case 'e':       /* blank padded day of month */
 			cp = number(cp, ep, (long)tm->tm_mday, -2, width, pad);
 			continue;
-		case 'f':	/* (AST) OBSOLETE use %Qf */
-			p = "%Qf";
+		case 'f':	/* Output the date in a format compatible with BusyBox %f */
+			p = "%Y.%m.%d-%H:%M:%S";
 			goto push;
 		case 'F':	/* ISO 8601:2000 standard date format */
 			p = "%Y-%m-%d";
@@ -316,8 +316,8 @@ tmxfmt(char* buf, size_t len, const char* format, Time_t t)
 		case 'J':	/* Julian date (0 offset) */
 			cp = number(cp, ep, (long)tm->tm_yday, 3, width, pad);
 			continue;
-		case 'k':	/* (AST) OBSOLETE use %QD */
-			p = "%QD";
+		case 'k':	/* hour (0 - 23) with blank padding */
+			p = "%_H";
 			goto push;
 		case 'K':	/* (AST) largest to smallest */
 			switch (alt)
@@ -333,8 +333,8 @@ tmxfmt(char* buf, size_t len, const char* format, Time_t t)
 				break;
 			}
 			goto push;
-		case 'l':	/* (AST) OBSOLETE use %QL */
-			p = "%QL";
+		case 'l':	/* hour (0 - 12) with blank padding */
+			p = "%_I";
 			goto push;
 		case 'L':	/* (AST) OBSOLETE use %Ql */
 			p = "%Ql";
@@ -364,9 +364,9 @@ tmxfmt(char* buf, size_t len, const char* format, Time_t t)
 			while (cp < ep && (n = *p++))
 				*cp++ = isupper(n) ? tolower(n) : n;
 			continue;
-		case 'q':	/* (AST) OBSOLETE use %Qz */
-			p = "%Qz";
-			goto push;
+		case 'q':	/* quarter of the year (1-4) */
+			cp = number(cp, ep, (long)(tm->tm_mon / 3) + 1, 0, width, pad);
+			continue;
 		case 'Q':	/* (AST) %Q<alpha> or %Q<delim>recent<delim>distant<delim> */
 			if (c = *format)
 			{
diff --git a/src/lib/libcmd/date.c b/src/lib/libcmd/date.c
index 3f9a3031f..dd8ad9cd4 100644
--- a/src/lib/libcmd/date.c
+++ b/src/lib/libcmd/date.c
@@ -95,26 +95,26 @@ USAGE_LICENSE
 "		[+d?day of month number]"
 "		[+D?date as \amm/dd/yy\a]"
 "		[+e?blank padded day of month number]"
-"		[+f?locale default override date format]"
+"		[+f?print a date with the format '\%Y.\%m.\%d-\%H:\%M:\%S']"
 "		[+F?%ISO 8601:2000 standard date format; equivalent to Y-%m-%d]"
 "		[+g?\bls\b(1) \b-l\b recent date with \ahh:mm\a]"
 "		[+G?\bls\b(1) \b-l\b distant date with \ayyyy\a]"
 "		[+h?abbreviated month name]"
-"		[+H?24-hour clock hour]"
+"		[+H?24-hour clock hour, zero-padded]"
 "		[+i?international \bdate\b(1) date with time zone type name]"
-"		[+I?12-hour clock hour]"
+"		[+I?12-hour clock hour, zero-padded]"
 "		[+j?1-offset Julian date]"
 "		[+J?0-offset Julian date]"
-"		[+k?\bdate\b(1) style date]"
+"		[+k?24-hour clock hour, blank-padded]"
 "		[+K?all numeric date; equivalent to \b%Y-%m-%d+%H:%M:%S\b; \b%_[EO]]K\b for space separator, %OK adds \b.%N\b, \b%EK\b adds \b%.N%z\b, \b%_EK\b adds \b.%N %z\b]"
-"		[+l?\bls\b(1) \b-l\b date; equivalent to \b%Q/%g/%G/\b]"
+"		[+l?12-hour clock hour, blank-padded]"
 "		[+L?locale default date format]"
 "		[+m?month number]"
 "		[+M?minutes]"
 "		[+n?newline character]"
 "		[+N?nanoseconds 000000000-999999999]"
 "		[+p?meridian (e.g., \bAM\b or \bPM\b)]"
-"		[+q?time zone type name (nation code)]"
+"		[+q?quarter of the year]"
 "		[+Q?\a<del>recent<del>distant<del>\a: \a<del>\a is a unique"
 "			delimter character; \arecent\a format for recent"
 "			dates, \adistant\a format otherwise]"