diff --git a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-1.yaml b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-1.yaml
index 6e0239402e63255059050f4838edadee37aba8c0..75a08ef29c18d90d070e87869ed7923a0cb9fa6b 100644
--- a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-1.yaml
+++ b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-1.yaml
@@ -8,7 +8,7 @@ pyxis-1:
     nb_threads: 256
     platform_type: aarch64
   bios:
-    release_date: 08/13/2020
+    release_date: '08/13/2020'
     vendor: GIGABYTE
     version: F34
   bmc_version: '12.46'
diff --git a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-2.yaml b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-2.yaml
index bfd0052fed5142b3a5a1d82c78cba31b59462a63..441678484b67abee6d773d7fd068efcd865129ee 100644
--- a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-2.yaml
+++ b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-2.yaml
@@ -8,7 +8,7 @@ pyxis-2:
     nb_threads: 256
     platform_type: aarch64
   bios:
-    release_date: 08/13/2020
+    release_date: '08/13/2020'
     vendor: GIGABYTE
     version: F34
   bmc_version: '12.46'
diff --git a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-3.yaml b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-3.yaml
index 351b762b129d2baa80d0386c6f18ad401289fa0c..1b08327f65c9cad3bcd64bb9ccda8d08c3326880 100644
--- a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-3.yaml
+++ b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-3.yaml
@@ -8,7 +8,7 @@ pyxis-3:
     nb_threads: 256
     platform_type: aarch64
   bios:
-    release_date: 08/13/2020
+    release_date: '08/13/2020'
     vendor: GIGABYTE
     version: F34
   bmc_version: '12.46'
diff --git a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-4.yaml b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-4.yaml
index 8c33e0b8045df44f58c6034522b44a0c93fe1789..e11a6511250da16e8f1b11334ce2f28a7b42d07f 100644
--- a/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-4.yaml
+++ b/input/grid5000/sites/lyon/clusters/pyxis/nodes/pyxis-4.yaml
@@ -8,7 +8,7 @@ pyxis-4:
     nb_threads: 256
     platform_type: aarch64
   bios:
-    release_date: 08/13/2020
+    release_date: '08/13/2020'
     vendor: GIGABYTE
     version: F34
   bmc_version: '12.46'