diff --git a/src/georinex/nav2.py b/src/georinex/nav2.py
index de985d8..231e8ed 100644
--- a/src/georinex/nav2.py
+++ b/src/georinex/nav2.py
@@ -195,6 +195,8 @@ def rinexnav2(fn: T.TextIO | Path, tlim: tuple[datetime, datetime] | None = None
             nav[name] *= 1e3
 
     # %% other attributes
+    if "LEAP SECONDS" in header:
+        nav.attrs["leap_seconds"] = int(header["LEAP SECONDS"])
     nav.attrs["version"] = header["version"]
     nav.attrs["svtype"] = [svtype]  # Use list for consistency with NAV3.
     nav.attrs["rinextype"] = "nav"
@@ -208,6 +210,13 @@ def rinexnav2(fn: T.TextIO | Path, tlim: tuple[datetime, datetime] | None = None
         beta = [rinex_string_to_float(beta[2 + i * 12 : 2 + (i + 1) * 12]) for i in range(4)]
         nav.attrs["ionospheric_corr_GPS"] = np.hstack((alpha, beta))
 
+    if "DELTA-UTC: A0,A1,T,W" in header:
+        delta_utc = header["DELTA-UTC: A0,A1,T,W"]
+        nav.attrs["A0"] = rinex_string_to_float(delta_utc[2 : 22])
+        nav.attrs["A1"] = rinex_string_to_float(delta_utc[22 : 42])
+        nav.attrs["Tot"] = rinex_string_to_float(delta_utc[42 : 52])
+        nav.attrs["Wnt"] = rinex_string_to_float(delta_utc[52 : 59])
+
     return nav
 
 
diff --git a/src/georinex/nav3.py b/src/georinex/nav3.py
index aa936f8..ed8706f 100644
--- a/src/georinex/nav3.py
+++ b/src/georinex/nav3.py
@@ -78,7 +78,6 @@ def rinexnav3(
                 raw += ln[STARTCOL3:80]
             # one line per SV
             raws.append(raw.replace("D", "E").replace("\n", ""))
-
     # %% parse collected data per SV
     # NOTE: must be 'ns' or .to_netcdf will fail!
     t = np.array([np.datetime64(t, "ns") for t in times])
@@ -153,7 +152,8 @@ def rinexnav3(
             nav.attrs["ionospheric_corr_BDS"] = np.hstack((corr["BDSA"], corr["BDSB"]))
         if "IRNA" in corr and "IRNB" in corr:
             nav.attrs["ionospheric_corr_IRN"] = np.hstack((corr["IRNA"], corr["IRNB"]))
-
+    if "LEAP SECONDS" in header:
+        nav.attrs["leap_seconds"] = int(header["LEAP SECONDS"].split()[0])
     nav.attrs["version"] = header["version"]
     nav.attrs["svtype"] = svtypes
     nav.attrs["rinextype"] = "nav"
@@ -230,9 +230,10 @@ def _sparefields(cf: list[str], sys: str, N: int) -> list[str]:
         elif N == 27:  # no middle or trailing spare fields
             cf = cf[:22] + cf[23:-3]
     elif sys == "I":
-        if N == 28:
+        if N == 26:
+            cf = cf[:22] + cf[23:26] + [cf[27]]
+        elif N == 28:
             cf = cf[:28]
-
     if N != len(cf):
         raise ValueError(f"System {sys} NAV data is not the same length as the number of fields.")
 
diff --git a/src/georinex/obs2.py b/src/georinex/obs2.py
index 292db34..f4c1c8e 100644
--- a/src/georinex/obs2.py
+++ b/src/georinex/obs2.py
@@ -305,10 +305,11 @@ def rinexsystem2(
         obs.attrs["rxmodel"] = hdr["rxmodel"]
     if "position" in hdr.keys():
         obs.attrs["position"] = hdr["position"]
-
     if "position_geodetic" in hdr.keys():
         obs.attrs["position_geodetic"] = hdr["position_geodetic"]
-
+    if "LEAP SECONDS" in hdr.keys():
+        obs.attrs["leap_seconds"] = int(hdr["LEAP SECONDS"])
+        
     return obs
 
 
@@ -450,11 +451,14 @@ def obsheader2(
     except (KeyError, ValueError):
         pass
 
-    try:  # This key is OPTIONAL
+    try:  
         hdr["interval"] = float(hdr["INTERVAL"][:10])
     except (KeyError, ValueError):
         pass
-
+    try:  
+        hdr["version"] = float(hdr["RINEX VERSION / TYPE"].split()[0])
+    except (KeyError, ValueError):
+        pass
     try:
         s = " "
         hdr["rxmodel"] = s.join(hdr["REC # / TYPE / VERS"].split()[1:-1])
diff --git a/src/georinex/obs3.py b/src/georinex/obs3.py
index a68dc21..89ce87a 100644
--- a/src/georinex/obs3.py
+++ b/src/georinex/obs3.py
@@ -160,7 +160,8 @@ def rinexobs3(
             data.attrs["receiver_clock_offset_applied"] = int(hdr["RCV CLOCK OFFS APPL"])
         except ValueError:
             pass
-
+    if "LEAP SECONDS" in hdr.keys():
+        data.attrs["leap_seconds"] = int(hdr["LEAP SECONDS"])
     return data
 
 
diff --git a/src/georinex/tests/test_nav2.py b/src/georinex/tests/test_nav2.py
index 127b8a2..d71d623 100755
--- a/src/georinex/tests/test_nav2.py
+++ b/src/georinex/tests/test_nav2.py
@@ -207,3 +207,15 @@ def test_ionospheric_correction():
             -0.5243e06,
         ]
     )
+
+
+def test_delta_utc():
+    nav = gr.load(R / "14601736.18n")
+    assert [nav.A0, nav.A1, nav.Tot, nav.Wnt] == approx(
+        [
+            -0.186264514923e-08,
+            -0.888178419700e-15,
+            61440.0,
+            2006.0
+        ]
+    )