feat: fix leap year rules, add year and month to the delay string

backend/src/humanizeDuration.ts

@@ -0,0 +1,34 @@
+import humanizeduration from "humanize-duration";
+
+export const delayStringMultipliers = {
+  y: 1000 * 60 * 60 * 24 * (365 + 1 / 4 - 1 / 100 + 1 / 400),
+  mo: 1000 * 60 * 60* 24 * (365 + 1 / 4 - 1 / 100 + 1 / 400) / 12,
+  w: 1000 * 60 * 60 * 24 * 7,
+  d: 1000 * 60 * 60 * 24,
+  h: 1000 * 60 * 60,
+  m: 1000 * 60,
+  s: 1000,
+  x: 1,
+};
+
+export const humanizeDurationShort = humanizeduration.humanizer({
+  language: "shortEn",
+  languages: {
+    shortEn: {
+      y: () => "y",
+      mo: () => "mo",
+      w: () => "w",
+      d: () => "d",
+      h: () => "h",
+      m: () => "m",
+      s: () => "s",
+      ms: () => "ms",
+    },
+  },
+  spacer: "",
+  unitMeasures: delayStringMultipliers
+});
+
+export const humanizeDuration = humanizeduration.humanizer({
+  unitMeasures: delayStringMultipliers
+});