Added some date/time basics. (0.19.0)

lib/utils/datetime.fun

@@ -0,0 +1,32 @@
+// Date/time utilities abstraction for the Fun stdlib.
+// Minimal version to validate syntax.
+
+/*
+ * Date/time utilities abstraction for the Fun stdlib.
+ * Provides a convenient class-based API over VM date/time opcodes.
+ *
+ * Methods:
+ *  - now_ms()    -> current wall clock ms since Unix epoch
+ *  - mono_ms()   -> monotonic clock ms (for measuring intervals)
+ *  - format(ms, fmt) -> format an epoch-ms timestamp using strftime format
+ *  - iso_now()   -> ISO-8601 like local timestamp (YYYY-MM-DDTHH:MM:SS)
+ */
+
+class DateTime()
+  // Current wall-clock time in milliseconds since Unix epoch
+  fun now_ms(this)
+    return time_now_ms()
+
+  // Monotonic clock in milliseconds
+  fun mono_ms(this)
+    return clock_mono_ms()
+
+  // Format an epoch-ms timestamp with a strftime() format string
+  fun format(this, ms, fmt)
+    // ensure argument order and types are okay
+    return date_format(to_number(ms), to_string(fmt))
+
+  // Convenience: ISO-like current datetime string (local time)
+  fun iso_now(this)
+    ms = time_now_ms()
+    return date_format(ms, "%Y-%m-%dT%H:%M:%S")