@@ -0,0 +1 @@
+The Zarr format 2 time dtypes accept the generic time unit in brackets — `<M8[generic]`, or `<m8[2generic]` with a scale — the spellings zarr-python writes for a NumPy generic-unit time dtype. A unit is still required: the unitless `<M8` stays refused, as the v2 spec demands.
@@ -24,8 +24,9 @@
     "ps",
     "fs",
     "as",
+    "generic",
 )
-"""The units NumPy accepts for a datetime64 or timedelta64 (https://numpy.org/doc/stable/reference/arrays.datetime.html#datetime-units). The v3 types also accept `"generic"`."""
+"""The units NumPy accepts for a datetime64 or timedelta64 (https://numpy.org/doc/stable/reference/arrays.datetime.html#datetime-units), and `"generic"`, NumPy's unit-less unit, which NumPy parses in brackets (`<M8[generic]`) though its own `dtype.str` omits it. The v2 spec's unit table does not list `generic`, but zarr-python writes it (zarr-developers/zarr-python#4580)."""
 
 NUMPY_TIME_MAX_SCALE_FACTOR: Final = 2**31 - 1
 """The largest `scale_factor` that numpy stores, because the field is a signed int32."""
 
@@ -14,7 +14,7 @@
 ]
 """The time unit codes of the numpy time types, `numpy.datetime64` and `numpy.timedelta64`."""
 
-NUMPY_TIME_UNIT: Final = (*NUMPY_TIME_UNITS, "generic")
+NUMPY_TIME_UNIT: Final = NUMPY_TIME_UNITS
 """Runtime tuple of the permitted `numpy.timedelta64`/`numpy.datetime64` unit strings."""
 
 numpy_time_storage: Final = multi_byte
 
@@ -61,7 +61,9 @@ def _read(value: object) -> tuple[type, list[tuple[Loc, str]]]:
         ("<M8[ns]", "datetime64", "<M8[ns]"),
         (">M8[10s]", "datetime64", ">M8[10s]"),
         ("<M8[μs]", "datetime64", "<M8[us]"),
+        ("<M8[generic]", "datetime64", "<M8[generic]"),
         ("<m8[D]", "timedelta64", "<m8[D]"),
+        (">m8[2generic]", "timedelta64", ">m8[2generic]"),
         ([["x", "<f4"], ["y", "<i4", [2]]], "struct", (("x", "<f4"), ("y", "<i4", (2,)))),
         ([["r", "|u1"], ["s", [["t", "<f4"]]]], "struct", (("r", "|u1"), ("s", (("t", "<f4"),)))),
         # NumPy names the padding fields of an aligned struct "", and zarr 2.x writes them.
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+The Zarr format 2 time dtypes accept the generic time unit in brackets — `<M8[generic]`, or `<m8[2generic]` with a scale — the spellings zarr-python writes for a NumPy generic-unit time dtype. A unit is still required: the unitless `<M8` stays refused, as the v2 spec demands.
Original file line number	Diff line number	Diff line change
`@@ -14,7 +14,7 @@`
`14`	`14`	`]`
`15`	`15`	"""The time unit codes of the numpy time types, `numpy.datetime64` and `numpy.timedelta64`."""
`16`	`16`
`17`		`-NUMPY_TIME_UNIT: Final = (*NUMPY_TIME_UNITS, "generic")`
	`17`	`+NUMPY_TIME_UNIT: Final = NUMPY_TIME_UNITS`
`18`	`18`	"""Runtime tuple of the permitted `numpy.timedelta64`/`numpy.datetime64` unit strings."""
`19`	`19`
`20`	`20`	`numpy_time_storage: Final = multi_byte`