diff --git a/my/common.py b/my/common.py
index 2c241cd..89ee916 100644
--- a/my/common.py
+++ b/my/common.py
@@ -1,7 +1,7 @@
 from pathlib import Path
 import functools
 import types
-from typing import Union, Callable, Dict, Iterable, TypeVar, Sequence, List, Optional, Any, cast
+from typing import Union, Callable, Dict, Iterable, TypeVar, Sequence, List, Optional, Any, cast, Tuple
 
 from . import init
 
@@ -46,6 +46,7 @@ def the(l: Iterable[T]) -> T:
     return first
 
 
+# TODO more_itertools.bucket?
 def group_by_key(l: Iterable[T], key: Callable[[T], K]) -> Dict[K, List[T]]:
     res: Dict[K, List[T]] = {}
     for i in l:
@@ -106,9 +107,11 @@ from .kython.klogging import setup_logger, LazyLogger
 
 Paths = Union[Sequence[PathIsh], PathIsh]
 
-def get_files(pp: Paths, glob: str, sort: bool=True) -> List[Path]:
+def get_files(pp: Paths, glob: str, sort: bool=True) -> Tuple[Path, ...]:
     """
     Helper function to avoid boilerplate.
+
+    Tuple as return type is a bit friendlier for hashing/caching, so hopefully makes sense
     """
     # TODO FIXME mm, some wrapper to assert iterator isn't empty?
     sources: List[Path] = []
@@ -129,7 +132,7 @@ def get_files(pp: Paths, glob: str, sort: bool=True) -> List[Path]:
 
     if sort:
         paths = list(sorted(paths))
-    return paths
+    return tuple(paths)
 
 
 def mcachew(*args, **kwargs):
diff --git a/my/emfit/__init__.py b/my/emfit/__init__.py
index b245824..2b8f5a8 100755
--- a/my/emfit/__init__.py
+++ b/my/emfit/__init__.py
@@ -5,26 +5,21 @@
 Consumes data exported by https://github.com/karlicoss/backup-emfit
 """
 import json
-import logging
-from collections import OrderedDict as odict
 from dataclasses import dataclass
 from datetime import date, datetime, time, timedelta
+from itertools import groupby
 from pathlib import Path
 from typing import Dict, Iterator, List, NamedTuple, Any, cast
 
 import pytz
+from more_itertools import bucket
 
-from ..common import get_files, LazyLogger, cproperty, group_by_key, mcachew
+from ..common import get_files, LazyLogger, cproperty, mcachew
 
 from my.config import emfit as config
 
 
-logger = LazyLogger('my.emfit', level='info')
-
-
-# TODO FIXME remove?
-import kython
-timed = lambda f: kython.timed(f, logger=logger)
+logger = LazyLogger(__name__, level='info')
 
 
 def hhmm(minutes):
@@ -35,13 +30,10 @@ AWAKE = 4
 
 Sid = str
 
-# TODO use tz provider for that?
-_TZ = pytz.timezone(config.tz)
-
 # TODO use common tz thing?
 def fromts(ts) -> datetime:
-    dt = datetime.fromtimestamp(ts)
-    return _TZ.localize(dt)
+    dt = datetime.fromtimestamp(ts, tz=pytz.utc)
+    return dt
 
 
 class Mixin:
@@ -295,14 +287,14 @@ class Emfit(Mixin):
 
 # TODO move to common?
 def dir_hash(path: Path):
-    mtimes = tuple(p.stat().st_mtime for p in sorted(path.glob('*.json')))
+    mtimes = tuple(p.stat().st_mtime for p in get_files(path, glob='*.json'))
     return mtimes
 
 
+# TODO take __file__ into account somehow?
 @mcachew(cache_path=config.cache_path, hashf=dir_hash, logger=logger)
-def iter_datas_cached(path: Path) -> Iterator[Emfit]:
-    # TODO use get_files?
-    for f in sorted(path.glob('*.json')):
+def iter_datas(path: Path=config.export_path) -> Iterator[Emfit]:
+    for f in get_files(path, glob='*.json'):
         sid = f.stem
         if sid in config.excluded_sids:
             continue
@@ -311,20 +303,17 @@ def iter_datas_cached(path: Path) -> Iterator[Emfit]:
         yield from Emfit.make(em)
 
 
-def iter_datas(path=config.export_path) -> Iterator[Emfit]:
-    yield from iter_datas_cached(path)
-
-
 def get_datas() -> List[Emfit]:
     return list(sorted(iter_datas(), key=lambda e: e.start))
 # TODO move away old entries if there is a diff??
 
 
-@timed
 def by_night() -> Dict[date, Emfit]:
-    res: Dict[date, Emfit] = odict()
+    res: Dict[date, Emfit] = {}
     # TODO shit. I need some sort of interrupted sleep detection?
-    for dd, sleeps in group_by_key(get_datas(), key=lambda s: s.date).items():
+    grouped = bucket(get_datas(), key=lambda s: s.date)
+    for dd in grouped:
+        sleeps = list(grouped[dd])
         if len(sleeps) > 1:
             logger.warning("multiple sleeps per night, not handled yet: %s", sleeps)
             continue
diff --git a/my/foursquare.py b/my/foursquare.py
index 03cc312..ed55a24 100755
--- a/my/foursquare.py
+++ b/my/foursquare.py
@@ -15,10 +15,10 @@ from .common import get_files, LazyLogger
 from my.config import foursquare as config
 
 
-logger = LazyLogger(__package__)
+logger = LazyLogger(__name__)
 
 
-def _get_exports() -> List[Path]:
+def inputs():
     return get_files(config.export_path, '*.json')
 
 
@@ -62,7 +62,7 @@ class Place:
 
 def get_raw(fname=None):
     if fname is None:
-        fname = max(_get_exports())
+        fname = max(inputs())
     j = json.loads(Path(fname).read_text())
     assert isinstance(j, list)
 
diff --git a/my/rescuetime.py b/my/rescuetime.py
index 3ee2730..5bf136c 100644
--- a/my/rescuetime.py
+++ b/my/rescuetime.py
@@ -18,7 +18,7 @@ from my.config import rescuetime as config
 log = LazyLogger(__package__, level='info')
 
 
-def _get_exports() -> List[Path]:
+def inputs():
     return get_files(config.export_path, '*.json')
 
 
@@ -28,7 +28,7 @@ Model = rescuexport.Model
 
 # TODO cache?
 def get_model(last=0) -> Model:
-    return Model(_get_exports()[-last:])
+    return Model(inputs()[-last:])
 
 
 def _without_errors():
diff --git a/setup.py b/setup.py
index ddf25fb..233829a 100644
--- a/setup.py
+++ b/setup.py
@@ -4,8 +4,9 @@
 from setuptools import setup, find_namespace_packages # type: ignore
 
 INSTALL_REQUIRES = [
-    'appdirs',
-    'pytz', # even though it's not needed by the core, it's so common anyway...
+    'pytz',           # even though it's not needed by the core, it's so common anyway...
+    'appdirs',        # very common, and makes it portable
+    'more-itertools', # it's just too useful and very common anyway
 ]