diff --git a/machines/web01/crabfit/packages/crabfit-frontend/07-colormap.patch b/machines/web01/crabfit/packages/crabfit-frontend/07-colormap.patch
new file mode 100644
index 0000000..4eee47c
--- /dev/null
+++ b/machines/web01/crabfit/packages/crabfit-frontend/07-colormap.patch
@@ -0,0 +1,15 @@
+diff --git a/src/utils/calculateAvailability.ts b/src/utils/calculateAvailability.ts
+index 67286f35..4a744672 100644
+--- a/src/utils/calculateAvailability.ts
++++ b/src/utils/calculateAvailability.ts
+@@ -23,8 +23,8 @@ interface AvailabilityInfo {
+  * group availability for each date passed in.
+  */
+ export const calculateAvailability = (dates: string[], people: Person[]): AvailabilityInfo => {
+-  let min = 0
+-  let max = people.length
++  let min = people.length
++  let max = 0
+ 
+   const availabilities: Availability[] = dates.map(date => {
+     const names = people.flatMap(p => p.availability.some(d => d === date) ? [p.name] : [])
diff --git a/machines/web01/crabfit/packages/crabfit-frontend/default.nix b/machines/web01/crabfit/packages/crabfit-frontend/default.nix
index d89830e..a2280ff 100644
--- a/machines/web01/crabfit/packages/crabfit-frontend/default.nix
+++ b/machines/web01/crabfit/packages/crabfit-frontend/default.nix
@@ -32,6 +32,7 @@ stdenv.mkDerivation (
       ./04-frontend_url.patch
       ./05-dgnum.patch
       ./06-download.patch
+      ./07-colormap.patch
     ];
 
     offlineCache = fetchYarnDeps {