diff --git a/man/remind.1.in b/man/remind.1.in
index 792f17a6..a2376d8c 100644
--- a/man/remind.1.in
+++ b/man/remind.1.in
@@ -3044,6 +3044,11 @@ This variable can be set only to ":" or ".".  It holds the character
 used to separate portions of a time when \fBRemind\fR prints a TIME or
 DATETIME value.
 .TP
+.B $TimetIs64bit (read-only)
+This variable returns 1 if the internal C \fBtime_t\fR type is at least
+64 bits long.  If it returns 0, then some astronomical functions such as
+solstice and equinox calculations will fail after the year 2037.
+.TP
 .B $UntimedFirst (read-only)
 Set to 1 if the \fB\-g\fR option is used with a fourth sort character
 of "d"; set to 0 otherwise.
diff --git a/src/var.c b/src/var.c
index 16ad8e52..7989cd58 100644
--- a/src/var.c
+++ b/src/var.c
@@ -269,6 +269,18 @@ static int trig_day_func(int do_set, Value *val)
     return OK;
 }
 
+static int timet_is_64_func(int do_set, Value *val)
+{
+    UNUSED(do_set);
+    val->type = INT_TYPE;
+    if (sizeof(time_t) >= (64 / CHAR_BIT)) {
+        val->v.val = 1;
+    } else {
+        val->v.val = 0;
+    }
+    return OK;
+}
+
 static int trig_mon_func(int do_set, Value *val)
 {
     int y, m, d;
@@ -938,6 +950,7 @@ static SysVar SysVarArr[] = {
     {"TerminalBackground", 0, SPECIAL_TYPE,  terminal_bg_func, 0,      0 },
     {"Thursday",       1,  TRANS_TYPE,   "Thursday",           0,      0 },
     {"TimeSep",        1,  SPECIAL_TYPE, time_sep_func,        0,      0 },
+    {"TimetIs64bit",   0,  SPECIAL_TYPE, timet_is_64_func,     0,      0 },
     {"Tm",             0,  SPECIAL_TYPE, trig_mon_func,        0,      0 },
     {"Today",          1,  TRANS_TYPE,   "today",              0,      0 },
     {"Tomorrow",       1,  TRANS_TYPE,   "tomorrow",           0,      0 },
diff --git a/tests/test-rem b/tests/test-rem
index a1385eee..9ff54d18 100644
--- a/tests/test-rem
+++ b/tests/test-rem
@@ -59,7 +59,7 @@ chmod 000 include_dir/04cantread.rem
 TEST_GETENV="foo bar baz" ; export TEST_GETENV
 echo "Test 1" > ../tests/test.out
 echo "" >> ../tests/test.out
-../src/remind -e -dxte ../tests/test.rem 16 feb 1991 12:13 >> ../tests/test.out 2>&1
+../src/remind -e -dxte ../tests/test.rem 16 feb 1991 12:13 2>&1 | grep -v 'TimetIs64bit' >> ../tests/test.out
 echo "" >> ../tests/test.out
 echo "Test 2" >> ../tests/test.out
 echo "" >> ../tests/test.out
diff --git a/tests/test.cmp b/tests/test.cmp
index aefea631..4f07e12d 100644
--- a/tests/test.cmp
+++ b/tests/test.cmp
@@ -1381,7 +1381,7 @@ trigeventstart() => 1991-02-13@16:00
 set a135 trigeventduration()
 trigeventduration() => 72:00
 set a136 stdout()
-stdout() => "FILE"
+stdout() => "PIPE"
 
 # These will issue errors
 REM Mon OMIT Mon SKIP MSG Never ever ever...
@@ -2727,7 +2727,7 @@ a047  -1
 a135  72:00
 a097  -3
 a048  "foo"
-a136  "FILE"
+a136  "PIPE"
 a098  0
 a049  21
 a099  -1
@@ -24286,6 +24286,7 @@ $Td
 $TerminalBackground
 $Thursday
 $TimeSep
+$TimetIs64bit
 $Tm
 $Today
 $Tomorrow