diff --git a/get_time_freq_detection.py b/get_time_freq_detection.py
index 5db9aa43c0cbb8a356d50800f7b410c1eba189d8..c71d873612243dbefaa2d4255e78f35e69a4e891 100644
--- a/get_time_freq_detection.py
+++ b/get_time_freq_detection.py
@@ -49,6 +49,9 @@ df['midl'] = (df.x*DUREE_SPECTRO)+(df.idx.astype(int))
 df['freq_center'] = (1-df.y)*(SR/2)
 df['freq_min'] = df.freq_center - (df.h*(SR/2))/2
 df['freq_max'] = df.freq_center + (df.h*(SR/2))/2
+df['start'] = df.midl - (df.w * DUREE_SPECTRO)/2
+df['stop'] = df.midl + (df.w * DUREE_SPECTRO)/2
+df['duration'] = df.stop - df.start
 
 df.to_csv(os.path.join(outdir,str(out_file+'.csv')), index= False)
 print('saved as ',os.path.join(outdir,str(out_file+'.csv')))