Use UTC time instead of local time

3 files changed, 17 insertions, 22 deletions

diff --git a/fg21sim/sky.py b/fg21sim/sky.py
index 2b94c7c..a016cb6 100644
--- a/fg21sim/sky.py
+++ b/fg21sim/sky.py
@@ -1,5 +1,5 @@
-# Copyright (c) 2017 Weitian LI <weitian@aaronly.me>
-# MIT license
+# Copyright (c) 2017,2019 Weitian LI <wt@liwt.net>
+# MIT License
 
 """
 Generic simulation sky supporting both sky patch and HEALPix all-sky
@@ -13,7 +13,7 @@ References
 
 import logging
 import copy
-from datetime import datetime, timezone
+from datetime import datetime
 
 import numpy as np
 from scipy import ndimage
@@ -253,7 +253,7 @@ class SkyBase:
         hdr["PixSize"] = (self.pixelsize, "Pixel size [arcsec]")
         hdr["CREATOR"] = (self.creator, "Sky Creator")
         hdr["FREQ"] = (self.frequency, "Sky frequency [MHz]")
-        hdr["DATE"] = (datetime.now(timezone.utc).astimezone().isoformat(),
+        hdr["DATE"] = (datetime.utcnow().isoformat()+"Z",
                        "File creation date")
         return hdr
 
diff --git a/fg21sim/utils/healpix.py b/fg21sim/utils/healpix.py
index 9ec210b..2c5d9ba 100644
--- a/fg21sim/utils/healpix.py
+++ b/fg21sim/utils/healpix.py
@@ -1,5 +1,5 @@
-# Copyright (c) 2016 Weitian LI <liweitianux@live.com>
-# MIT license
+# Copyright (c) 2016,2019 Weitian LI <wt@liwt.net>
+# MIT License
 #
 # References:
 # [1] K. M. Gorski, et al. 2005, ApJ, 622, 759
@@ -25,7 +25,7 @@ hpx2healpix:
 """
 
 
-from datetime import datetime, timezone
+from datetime import datetime
 import logging
 
 import numpy as np
@@ -301,9 +301,8 @@ def _make_hpx_header(header, append_history=None, append_comment=None):
     header["PV2_1"] = (4, "HPX H parameter (longitude)")
     header["PV2_2"] = (3, "HPX K parameter (latitude)")
     logger.info("Made HPX FITS header")
-    #
-    header["DATE"] = (datetime.now(timezone.utc).astimezone().isoformat(),
-                      "File creation date")
+
+    header["DATE"] = (datetime.utcnow().isoformat()+"Z", "File creation date")
     comments = [
         'The HPX coordinate system is an reorganization of the HEALPix',
         'data without regridding or interpolation, which is described in',
@@ -339,10 +338,8 @@ def _make_healpix_header(header, nside,
     header["FIRSTPIX"] = (0, "First pixel # (0 based)")
     header["LASTPIX"] = (npix-1, "Last pixel # (0 based)")
     logger.info("Made HEALPix FITS header")
-    #
-    header["DATE"] = (datetime.now(timezone.utc).astimezone().isoformat(),
-                      "File creation date")
-    #
+
+    header["DATE"] = (datetime.utcnow().isoformat()+"Z", "File creation date")
     if append_history is not None:
         logger.info("HEALPix FITS header: append history")
         for history in append_history:
diff --git a/fg21sim/utils/io.py b/fg21sim/utils/io.py
index b3666b6..b6719ec 100644
--- a/fg21sim/utils/io.py
+++ b/fg21sim/utils/io.py
@@ -1,5 +1,5 @@
-# Copyright (c) 2017 Weitian LI <weitian@aaronly.me>
-# MIT license
+# Copyright (c) 2017,2019 Weitian LI <wt@liwt.net>
+# MIT License
 
 """
 Input/output utilities
@@ -29,7 +29,7 @@ Input/output utilities
 import os
 import logging
 import pickle
-from datetime import datetime, timezone
+from datetime import datetime
 
 import numpy as np
 import pandas as pd
@@ -119,7 +119,7 @@ def dataframe_to_csv(df, outfile, comment=None, clobber=False):
     if comment is None:
         comment = [
             "by %s" % __name__,
-            "at %s" % datetime.now(timezone.utc).astimezone().isoformat(),
+            "at %sZ" % datetime.utcnow().isoformat(),
         ]
 
     with open(outfile, "w") as fh:
@@ -240,8 +240,7 @@ def write_fits_image(outfile, image, header=None, float32=False,
 
     hdr = fits.Header()
     hdr["CREATOR"] = (__name__, "File creator")
-    hdr["DATE"] = (datetime.now(timezone.utc).astimezone().isoformat(),
-                   "File creation date")
+    hdr["DATE"] = (datetime.utcnow().isoformat()+"Z", "File creation date")
     if header is not None:
         hdr.extend(header, update=True)
 
@@ -368,8 +367,7 @@ def write_fits_healpix(outfile, hpmap, header=None, float32=False,
     #
     hdr["EXTNAME"] = ("HEALPIX", "Name of the binary table extension")
     hdr["CREATOR"] = (__name__, "File creator")
-    hdr["DATE"] = (datetime.now(timezone.utc).astimezone().isoformat(),
-                   "File creation date")
+    hdr["DATE"] = (datetime.utcnow().isoformat()+"Z", "File creation date")
     # Merge user-provided header
     # NOTE: use the `.extend()` method instead of `.update()` method
     if header is not None: