diff --git a/.gitignore b/.gitignore
index f8c1d3b..19c73fe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,4 +12,4 @@ subprojects/zlib-*
 .DS_Store
 test/sizeof
 temp/*
-
+test/test_convert
diff --git a/test/test_convert.c b/test/test_convert.c
new file mode 100644
index 0000000..d8a64df
--- /dev/null
+++ b/test/test_convert.c
@@ -0,0 +1,23 @@
+/* test how conversions of integers to doubles affects the values */
+
+
+#include <stdio.h>
+#include <stdint.h>
+
+int main(int argc, char** argv){
+
+	int64_t nSec = 60L*60*24*( 365*55 + 13);  /* rough seconds in 55 years */
+	printf("64-Bit Int seconds in ~55 years      %ld\n", nSec);
+
+	double dSec = (double)nSec;
+	printf("Double seconds in ~55 years          %f\n", dSec);	
+
+	int64_t nNano = nSec * 1000000000 + 11111;  
+	printf("64-Bit Int nanoseconds in ~55 years  %ld\n", nNano);
+
+	double dNano = (double)nNano;
+
+	printf("Double nanoseconds in ~55 years      %f\n", dNano);
+	
+	printf("\nPrecision loss is about 100 nanosec @ 50 years.\n");
+}