--- nono/lib/test_mystring.cpp	2026/04/29 17:04:57	1.1.1.2
+++ nono/lib/test_mystring.cpp	2026/04/29 17:05:56	1.1.1.4
@@ -201,6 +201,9 @@ class Test_MyString : public TestClass
 		TESTDEF(startwith_ignorecase_1);
 		TESTDEF(string_split_1);
 		TESTDEF(string_split_2);
+		TESTDEF(format_number_1);
+		TESTDEF(SecToStr_1);
+		TESTDEF(TimeToStr_1);
 	}
 
 	void string_ltrim_1() {
@@ -379,6 +382,77 @@ class Test_MyString : public TestClass
 			xp_eq(exp, string_split(src, ',', num), t);
 		}
 	}
+
+	void format_number_1() {
+		TestTable<uint64, std::string> table = {
+			{ 0,			"0" },
+			{ 1,			"1" },
+			{ 999,			"999" },
+			{ 1000,			"1,000" },
+			{ 12345,		"12,345" },
+			{ 123456,		"123,456" },
+			{ 9876543,		"9,876,543" },
+			{ 987654321,	"987,654,321" },
+			{ 1000000000,	"1,000,000,000" },
+		};
+
+		for (const auto& t : table) {
+			auto        val = t.get<0>();
+			const auto& exp = t.get<1>();
+
+			xp_eq(exp, format_number(val), t);
+		}
+	}
+
+	void SecToStr_1() {
+		TestTable<uint64, std::string> table = {
+			{ 0,					            "0.000'000'000" },
+			{ 1,					            "0.000'000'001" },
+			{ 999999999,			            "0.999'999'999" },
+			{ 4300020001,			            "4.300'020'001" },
+			{ 9999999999,			            "9.999'999'999" },
+			{ 10000000001,			           "10.000'000'001" },
+			{ 100000000002,			          "100.000'000'002" },
+			{ 1000000000003,		         "1000.000'000'003" },
+			{ 10000000000004,		        "10000.000'000'004" },
+			{ 100000000000005,		       "100000.000'000'005" },
+			{ 1000000000000006,		      "1000000.000'000'006" },
+			{ 10000000000000007,	     "10000000.000'000'007" },
+			{ 100000000000000008,	    "100000000.000'000'008" },
+		};
+
+		for (const auto& t : table) {
+			auto        val = t.get<0>();
+			const auto& exp = t.get<1>();
+
+			xp_eq(exp, SecToStr(val), t);
+		}
+	}
+
+	void TimeToStr_1() {
+		TestTable<uint64, std::string> table = {
+			{ 0,					            "0.000'000'000" },
+			{ 1,					            "0.000'000'001" },
+			{ 999999999,			            "0.999'999'999" },
+			{ 4300020001,			            "4.300'020'001" },
+			{ 9999999999,			            "9.999'999'999" },
+			{ 10000000001,			           "10.000'000'001" },
+			{ 100000000002,			        " 1:40.000'000'002" },
+			{ 1000000000003,		        "16:40.000'000'003" },
+			{ 10000000000004,		     " 2:46:40.000'000'004" },
+			{ 100000000000005,		"  1d 03:46:40.000'000'005" },
+			{ 1000000000000006,		" 11d 13:46:40.000'000'006" },
+			{ 10000000000000007,	"115d 17:46:40.000'000'007" },
+			{ 100000000000000008,	"1157d 09:46:40.000'000'008" },
+		};
+
+		for (const auto& t : table) {
+			auto        val = t.get<0>();
+			const auto& exp = t.get<1>();
+
+			xp_eq(exp, TimeToStr(val), t);
+		}
+	}
 };
 
 int