diff --git a/.github/workflows/automatic_test.yml b/.github/workflows/automatic_test.yml
index c36c33d..26eb48a 100644
--- a/.github/workflows/automatic_test.yml
+++ b/.github/workflows/automatic_test.yml
@@ -12,11 +12,11 @@ jobs:
     steps:
       - name: Prepare the repo
         uses: actions/checkout@master
-      - name: Set up Python 3.7
+      - name: Set up Python 3.9
         uses: actions/setup-python@v1
         with:
-          python-version: 3.7
+          python-version: 3.9
       - name: Install packages
         run: pip install -r test/unittest/test_requirements.txt
       - name: Test
-        run: bash test/unittest/test_all.sh
\ No newline at end of file
+        run: bash test/unittest/test_all.sh
diff --git a/README.md b/README.md
index 1a1e490..d3a4e70 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
+[![DOI](https://zenodo.org/badge/406317261.svg)](https://zenodo.org/badge/latestdoi/406317261)
+
 # HydroAnalysis
 
-HydroAnalysis is a Python package to calculate indices and metrics useful in the everyday job of an hydrologist.
+[HydroAnalysis](https://pypi.org/project/hydroanalysis/) is a Python package to calculate indices and metrics useful in the everyday job of an hydrologist.
 
 The package is the result of the re-organization of code that I have used during my research and that I have decided to publish because of its supposed usefulness.
 
@@ -41,4 +43,4 @@ There is no systematic testing implemented here. However, the code has been manu
 
 ## Your contribution
 
-Please feel free to contribute to the package. If you have any suggestion or you want to contribute to the documentation, please contact the author and have a look at the documentation page explaining how to do it.
\ No newline at end of file
+Please feel free to contribute to the package. If you have any suggestion or you want to contribute to the documentation, please contact the author and have a look at the documentation page explaining how to do it.
diff --git a/hydroanalysis/meteo_indexes.py b/hydroanalysis/meteo_indexes.py
index 2eb3d73..aae03e9 100644
--- a/hydroanalysis/meteo_indexes.py
+++ b/hydroanalysis/meteo_indexes.py
@@ -216,7 +216,7 @@ def fit_t(pars, x, y):
     delta_t = temp_pars.x[0]
     st = temp_pars.x[1]
 
-    sig = delta_p * np.sign(delta_t) * np.cos(2 * np.pi * (sp - st / 365.25))
+    sig = delta_p * np.sign(delta_t) * np.cos(2 * np.pi * (sp - st) / 365.25)
 
     return(float(sig))
 
diff --git a/setup.py b/setup.py
index 4109155..aa14721 100644
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,7 @@
 
 setuptools.setup(
     name='hydroanalysis',
-    version='1.0.0',
+    version='1.0.1',
     author='Marco Dal Molin',
     author_email='marco.dalmolin.1991@gmail.com',
     description='Framework for calculating hydrological indices',
@@ -18,8 +18,8 @@
         'Topic :: Scientific/Engineering :: Hydrology',
     ],
     install_requires=[
-        'numpy>=1.20.*',
-        'pandas>=1.2.*',
-        'scipy>=1.6.*',
+        'numpy>=1.20.0',
+        'pandas>=1.2.0',
+        'scipy>=1.6.0',
     ],
-)
\ No newline at end of file
+)