diff --git a/build.zig b/build.zig
index 97f8a697803d7c98e31ff411960209b1d231e516..5c9f1bf73fb01aedcb3f18a8924905ced75c7e30 100644
--- a/build.zig
+++ b/build.zig
@@ -7,7 +7,7 @@ pub fn build(b: *std.Build) void {
     const disable_llvm = b.option(bool, "disable_llvm", "use the non-llvm zig codegen") orelse false;
 
     const t = b.addTest(.{
-        .root_source_file = b.path("main.zig"),
+        .root_source_file = b.path("test.zig"),
         .target = target,
         .optimize = mode,
     });
diff --git a/main.zig b/main.zig
deleted file mode 100644
index b1febcf680a765f3c3a0287175d010d23449b91d..0000000000000000000000000000000000000000
--- a/main.zig
+++ /dev/null
@@ -1,160 +0,0 @@
-const std = @import("std");
-const string = []const u8;
-const time = @import("time");
-
-pub fn main() !void {
-    std.log.info("All your codebase are belong to us.", .{});
-}
-
-fn harness(comptime seed: u64, comptime expects: []const [2]string) void {
-    for (0..expects.len) |i| {
-        _ = Case(seed, expects[i][0], expects[i][1]);
-    }
-}
-
-fn Case(comptime seed: u64, comptime fmt: string, comptime expected: string) type {
-    return struct {
-        test {
-            const alloc = std.testing.allocator;
-            const instant = time.DateTime.initUnixMs(seed);
-            const actual = try instant.formatAlloc(alloc, fmt);
-            defer alloc.free(actual);
-            std.testing.expectEqualStrings(expected, actual) catch return error.SkipZigTest;
-        }
-    };
-}
-
-fn expectFmt(instant: time.DateTime, comptime fmt: string, comptime expected: string) !void {
-    const alloc = std.testing.allocator;
-    const actual = try instant.formatAlloc(alloc, fmt);
-    defer alloc.free(actual);
-    std.testing.expectEqualStrings(expected, actual) catch return error.SkipZigTest;
-}
-
-comptime {
-    harness(0, &.{.{ "YYYY-MM-DD HH:mm:ss", "1970-01-01 00:00:00" }});
-    harness(1257894000000, &.{.{ "YYYY-MM-DD HH:mm:ss", "2009-11-10 23:00:00" }});
-    harness(1634858430000, &.{.{ "YYYY-MM-DD HH:mm:ss", "2021-10-21 23:20:30" }});
-    harness(1634858430023, &.{.{ "YYYY-MM-DD HH:mm:ss.SSS", "2021-10-21 23:20:30.023" }});
-    harness(1144509852789, &.{.{ "YYYY-MM-DD HH:mm:ss.SSS", "2006-04-08 15:24:12.789" }});
-
-    harness(1635033600000, &.{
-        .{ "H", "0" },  .{ "HH", "00" },
-        .{ "h", "12" }, .{ "hh", "12" },
-        .{ "k", "24" }, .{ "kk", "24" },
-    });
-
-    harness(1635037200000, &.{
-        .{ "H", "1" }, .{ "HH", "01" },
-        .{ "h", "1" }, .{ "hh", "01" },
-        .{ "k", "1" }, .{ "kk", "01" },
-    });
-
-    harness(1635076800000, &.{
-        .{ "H", "12" }, .{ "HH", "12" },
-        .{ "h", "12" }, .{ "hh", "12" },
-        .{ "k", "12" }, .{ "kk", "12" },
-    });
-    harness(1635080400000, &.{
-        .{ "H", "13" }, .{ "HH", "13" },
-        .{ "h", "1" },  .{ "hh", "01" },
-        .{ "k", "13" }, .{ "kk", "13" },
-    });
-
-    harness(1144509852789, &.{
-        .{ "M", "4" },
-        .{ "Mo", "4th" },
-        .{ "MM", "04" },
-        .{ "MMM", "Apr" },
-        .{ "MMMM", "April" },
-
-        .{ "Q", "2" },
-        .{ "Qo", "2nd" },
-
-        .{ "D", "8" },
-        .{ "Do", "8th" },
-        .{ "DD", "08" },
-
-        .{ "DDD", "98" },
-        .{ "DDDo", "98th" },
-        .{ "DDDD", "098" },
-
-        .{ "d", "6" },
-        .{ "do", "6th" },
-        .{ "dd", "Sa" },
-        .{ "ddd", "Sat" },
-        .{ "dddd", "Saturday" },
-        .{ "e", "6" },
-        .{ "E", "7" },
-
-        .{ "w", "14" },
-        .{ "wo", "14th" },
-        .{ "ww", "14" },
-
-        .{ "Y", "12006" },
-        .{ "YY", "06" },
-        .{ "YYY", "2006" },
-        .{ "YYYY", "2006" },
-
-        .{ "N", "AD" },
-        .{ "NN", "Anno Domini" },
-
-        .{ "A", "PM" },
-        .{ "a", "pm" },
-
-        .{ "H", "15" },
-        .{ "HH", "15" },
-        .{ "h", "3" },
-        .{ "hh", "03" },
-        .{ "k", "15" },
-        .{ "kk", "15" },
-
-        .{ "m", "24" },
-        .{ "mm", "24" },
-
-        .{ "s", "12" },
-        .{ "ss", "12" },
-
-        .{ "S", "7" },
-        .{ "SS", "78" },
-        .{ "SSS", "789" },
-
-        .{ "z", "UTC" },
-        .{ "Z", "+00:00" },
-        .{ "ZZ", "+0000" },
-
-        .{ "x", "1144509852789" },
-        .{ "X", "1144509852" },
-
-        .{ time.format.LT, "3:24 PM" },
-
-        .{ time.format.LTS, "3:24:12 PM" },
-
-        .{ time.format.L, "04/08/2006" },
-
-        .{ time.format.l, "4/8/2006" },
-
-        .{ time.format.LL, "April 8, 2006" },
-
-        .{ time.format.ll, "Apr 8, 2006" },
-
-        .{ time.format.LLL, "April 8, 2006 3:24 PM" },
-
-        .{ time.format.lll, "Apr 8, 2006 3:24 PM" },
-
-        .{ time.format.LLLL, "Saturday, April 8, 2006 3:24 PM" },
-
-        .{ time.format.llll, "Sat, Apr 8, 2006 3:24 PM" },
-    });
-
-    // https://github.com/nektro/zig-time/issues/3
-    harness(1144509852789, &.{.{ "YYYYMM", "200604" }});
-}
-
-// https://github.com/nektro/zig-time/issues/9
-test {
-    var t = time.DateTime.initUnix(1330502962);
-    try expectFmt(t, "YYYY-MM-DD hh:mm:ss A z", "2012-02-29 08:09:22 AM UTC");
-    t = t.addYears(1);
-    try expectFmt(t, "YYYY-MM-DD hh:mm:ss A z", "2013-03-01 08:09:22 AM UTC");
-}
diff --git a/test.zig b/test.zig
new file mode 100644
index 0000000000000000000000000000000000000000..b1febcf680a765f3c3a0287175d010d23449b91d
--- /dev/null
+++ b/test.zig
@@ -0,0 +1,160 @@
+const std = @import("std");
+const string = []const u8;
+const time = @import("time");
+
+pub fn main() !void {
+    std.log.info("All your codebase are belong to us.", .{});
+}
+
+fn harness(comptime seed: u64, comptime expects: []const [2]string) void {
+    for (0..expects.len) |i| {
+        _ = Case(seed, expects[i][0], expects[i][1]);
+    }
+}
+
+fn Case(comptime seed: u64, comptime fmt: string, comptime expected: string) type {
+    return struct {
+        test {
+            const alloc = std.testing.allocator;
+            const instant = time.DateTime.initUnixMs(seed);
+            const actual = try instant.formatAlloc(alloc, fmt);
+            defer alloc.free(actual);
+            std.testing.expectEqualStrings(expected, actual) catch return error.SkipZigTest;
+        }
+    };
+}
+
+fn expectFmt(instant: time.DateTime, comptime fmt: string, comptime expected: string) !void {
+    const alloc = std.testing.allocator;
+    const actual = try instant.formatAlloc(alloc, fmt);
+    defer alloc.free(actual);
+    std.testing.expectEqualStrings(expected, actual) catch return error.SkipZigTest;
+}
+
+comptime {
+    harness(0, &.{.{ "YYYY-MM-DD HH:mm:ss", "1970-01-01 00:00:00" }});
+    harness(1257894000000, &.{.{ "YYYY-MM-DD HH:mm:ss", "2009-11-10 23:00:00" }});
+    harness(1634858430000, &.{.{ "YYYY-MM-DD HH:mm:ss", "2021-10-21 23:20:30" }});
+    harness(1634858430023, &.{.{ "YYYY-MM-DD HH:mm:ss.SSS", "2021-10-21 23:20:30.023" }});
+    harness(1144509852789, &.{.{ "YYYY-MM-DD HH:mm:ss.SSS", "2006-04-08 15:24:12.789" }});
+
+    harness(1635033600000, &.{
+        .{ "H", "0" },  .{ "HH", "00" },
+        .{ "h", "12" }, .{ "hh", "12" },
+        .{ "k", "24" }, .{ "kk", "24" },
+    });
+
+    harness(1635037200000, &.{
+        .{ "H", "1" }, .{ "HH", "01" },
+        .{ "h", "1" }, .{ "hh", "01" },
+        .{ "k", "1" }, .{ "kk", "01" },
+    });
+
+    harness(1635076800000, &.{
+        .{ "H", "12" }, .{ "HH", "12" },
+        .{ "h", "12" }, .{ "hh", "12" },
+        .{ "k", "12" }, .{ "kk", "12" },
+    });
+    harness(1635080400000, &.{
+        .{ "H", "13" }, .{ "HH", "13" },
+        .{ "h", "1" },  .{ "hh", "01" },
+        .{ "k", "13" }, .{ "kk", "13" },
+    });
+
+    harness(1144509852789, &.{
+        .{ "M", "4" },
+        .{ "Mo", "4th" },
+        .{ "MM", "04" },
+        .{ "MMM", "Apr" },
+        .{ "MMMM", "April" },
+
+        .{ "Q", "2" },
+        .{ "Qo", "2nd" },
+
+        .{ "D", "8" },
+        .{ "Do", "8th" },
+        .{ "DD", "08" },
+
+        .{ "DDD", "98" },
+        .{ "DDDo", "98th" },
+        .{ "DDDD", "098" },
+
+        .{ "d", "6" },
+        .{ "do", "6th" },
+        .{ "dd", "Sa" },
+        .{ "ddd", "Sat" },
+        .{ "dddd", "Saturday" },
+        .{ "e", "6" },
+        .{ "E", "7" },
+
+        .{ "w", "14" },
+        .{ "wo", "14th" },
+        .{ "ww", "14" },
+
+        .{ "Y", "12006" },
+        .{ "YY", "06" },
+        .{ "YYY", "2006" },
+        .{ "YYYY", "2006" },
+
+        .{ "N", "AD" },
+        .{ "NN", "Anno Domini" },
+
+        .{ "A", "PM" },
+        .{ "a", "pm" },
+
+        .{ "H", "15" },
+        .{ "HH", "15" },
+        .{ "h", "3" },
+        .{ "hh", "03" },
+        .{ "k", "15" },
+        .{ "kk", "15" },
+
+        .{ "m", "24" },
+        .{ "mm", "24" },
+
+        .{ "s", "12" },
+        .{ "ss", "12" },
+
+        .{ "S", "7" },
+        .{ "SS", "78" },
+        .{ "SSS", "789" },
+
+        .{ "z", "UTC" },
+        .{ "Z", "+00:00" },
+        .{ "ZZ", "+0000" },
+
+        .{ "x", "1144509852789" },
+        .{ "X", "1144509852" },
+
+        .{ time.format.LT, "3:24 PM" },
+
+        .{ time.format.LTS, "3:24:12 PM" },
+
+        .{ time.format.L, "04/08/2006" },
+
+        .{ time.format.l, "4/8/2006" },
+
+        .{ time.format.LL, "April 8, 2006" },
+
+        .{ time.format.ll, "Apr 8, 2006" },
+
+        .{ time.format.LLL, "April 8, 2006 3:24 PM" },
+
+        .{ time.format.lll, "Apr 8, 2006 3:24 PM" },
+
+        .{ time.format.LLLL, "Saturday, April 8, 2006 3:24 PM" },
+
+        .{ time.format.llll, "Sat, Apr 8, 2006 3:24 PM" },
+    });
+
+    // https://github.com/nektro/zig-time/issues/3
+    harness(1144509852789, &.{.{ "YYYYMM", "200604" }});
+}
+
+// https://github.com/nektro/zig-time/issues/9
+test {
+    var t = time.DateTime.initUnix(1330502962);
+    try expectFmt(t, "YYYY-MM-DD hh:mm:ss A z", "2012-02-29 08:09:22 AM UTC");
+    t = t.addYears(1);
+    try expectFmt(t, "YYYY-MM-DD hh:mm:ss A z", "2013-03-01 08:09:22 AM UTC");
+}