diff --git a/src/components/cases/tasks-tab.tsx b/src/components/cases/tasks-tab.tsx
index 024aa9c..e2d2dd7 100644
--- a/src/components/cases/tasks-tab.tsx
+++ b/src/components/cases/tasks-tab.tsx
@@ -12,6 +12,7 @@ import { NewTaskDialog } from "@/components/tasks/new-task-dialog";
 import { ApplyWorkflowDialog } from "@/components/tasks/apply-workflow-dialog";
 import { cn } from "@/lib/utils";
 import { spawnNextWorkflowTask } from "@/lib/workflow-chain";
+import { parseDateOnly } from "@/lib/format";
 
 interface TaskRow {
   id: string;
@@ -130,7 +131,10 @@ export function CaseTasksTab({ caseId }: { caseId: string }) {
         )}
         {tasks.map((t) => {
           const ids = assigneesByTask[t.id] || [];
-          const overdue = t.due_date && t.status === "incomplete" && isBefore(startOfDay(new Date(t.due_date)), today);
+          const overdue =
+            t.due_date &&
+            t.status === "incomplete" &&
+            isBefore(startOfDay(parseDateOnly(t.due_date)!), today);
           return (
             <div
               key={t.id}
@@ -151,7 +155,7 @@ export function CaseTasksTab({ caseId }: { caseId: string }) {
               {t.due_date && (
                 <Badge variant={overdue ? "destructive" : "outline"} className="gap-1">
                   <CalIcon className="h-3 w-3" />
-                  {format(new Date(t.due_date), "MMM d")}
+                  {format(parseDateOnly(t.due_date)!, "MMM d")}
                 </Badge>
               )}
               <div className="flex -space-x-1.5">
diff --git a/src/components/collections/payment-plans-panel.tsx b/src/components/collections/payment-plans-panel.tsx
index ec2ff75..cef9093 100644
--- a/src/components/collections/payment-plans-panel.tsx
+++ b/src/components/collections/payment-plans-panel.tsx
@@ -25,7 +25,7 @@ import {
 } from "@/components/ui/select";
 import { CalendarClock, Loader2, Plus, Trash2 } from "lucide-react";
 import { toast } from "sonner";
-import { formatCurrency, formatDate } from "@/lib/format";
+import { formatCurrency, formatDate, parseDateOnly } from "@/lib/format";
 
 type Frequency = "weekly" | "biweekly" | "monthly";
 type PlanStatus = "active" | "completed" | "defaulted" | "cancelled";
@@ -200,7 +200,8 @@ export function PaymentPlansPanel({ collectionId }: { collectionId: string }) {
                   {ins.length > 0 && (
                     <div className="divide-y">
                       {ins.map((i) => {
-                        const overdue = !i.paid && new Date(i.due_date) < new Date(new Date().toDateString());
+                        const overdue =
+                          !i.paid && parseDateOnly(i.due_date)! < new Date(new Date().toDateString());
                         return (
                           <div key={i.id} className="flex items-center gap-3 p-2.5 px-3">
                             <Checkbox
diff --git a/src/components/tasks/task-detail-panel.tsx b/src/components/tasks/task-detail-panel.tsx
index 6315bbb..1c5bc46 100644
--- a/src/components/tasks/task-detail-panel.tsx
+++ b/src/components/tasks/task-detail-panel.tsx
@@ -38,6 +38,7 @@ import {
   DialogFooter,
 } from "@/components/ui/dialog";
 import { format } from "date-fns";
+import { parseDateOnly } from "@/lib/format";
 import type { Database } from "@/integrations/supabase/types";
 import { cn } from "@/lib/utils";
 import { createNotifications } from "@/lib/notifications";
@@ -453,13 +454,13 @@ export function TaskDetailPanel({
                   <PopoverTrigger asChild>
                     <Button variant="ghost" size="sm" className="h-7 px-2 text-sm font-normal">
                       <CalendarIcon className="h-3.5 w-3.5 mr-1.5" />
-                      {task.due_date ? format(new Date(task.due_date), "MM/dd/yyyy") : "Set date"}
+                      {task.due_date ? format(parseDateOnly(task.due_date)!, "MM/dd/yyyy") : "Set date"}
                     </Button>
                   </PopoverTrigger>
                   <PopoverContent align="start" className="p-0">
                     <Calendar
                       mode="single"
-                      selected={task.due_date ? new Date(task.due_date) : undefined}
+                      selected={task.due_date ? parseDateOnly(task.due_date)! : undefined}
                       onSelect={setDueDate}
                     />
                     {task.due_date && (
diff --git a/src/lib/format.ts b/src/lib/format.ts
index 943d822..c5392a9 100644
--- a/src/lib/format.ts
+++ b/src/lib/format.ts
@@ -3,6 +3,24 @@ export function formatCurrency(amount: number | string | null | undefined) {
   return new Intl.NumberFormat("en-US", { style: "currency", currency: "USD" }).format(n || 0);
 }
 
+/**
+ * Parse a date-only string ("YYYY-MM-DD") as a LOCAL date (midnight in the
+ * user's timezone). Using `new Date("2026-04-24")` parses as UTC midnight,
+ * which renders as the previous day in negative-offset timezones — that's
+ * the source of the "due date is one day earlier" bug.
+ *
+ * Returns null for falsy/invalid input. If a non date-only string or Date is
+ * passed, returns a Date built from it as-is.
+ */
+export function parseDateOnly(value: string | Date | null | undefined): Date | null {
+  if (!value) return null;
+  if (value instanceof Date) return value;
+  const m = value.match(/^(\d{4})-(\d{2})-(\d{2})$/);
+  if (m) return new Date(+m[1], +m[2] - 1, +m[3]);
+  const d = new Date(value);
+  return isNaN(d.getTime()) ? null : d;
+}
+
 export function formatDate(value: string | Date | null | undefined) {
   if (!value) return "—";
   // Date-only strings ("YYYY-MM-DD") must be rendered in UTC, otherwise
diff --git a/src/lib/workflow-chain.ts b/src/lib/workflow-chain.ts
index 660dedd..ea015b8 100644
--- a/src/lib/workflow-chain.ts
+++ b/src/lib/workflow-chain.ts
@@ -1,5 +1,17 @@
 import { supabase } from "@/integrations/supabase/client";
-import { addDays, format } from "date-fns";
+import { addDays } from "date-fns";
+
+/**
+ * Format a Date as "YYYY-MM-DD" using its UTC components. We do this so that
+ * a `completed_at` UTC timestamp like 2026-04-24T02:00:00Z (which is still
+ * Apr 23 in US local time) doesn't shift the computed due_date back a day.
+ */
+function toUTCDateString(d: Date): string {
+  const y = d.getUTCFullYear();
+  const m = String(d.getUTCMonth() + 1).padStart(2, "0");
+  const day = String(d.getUTCDate()).padStart(2, "0");
+  return `${y}-${m}-${day}`;
+}
 
 /**
  * After a task is marked complete, spawn the next task from its workflow
@@ -48,7 +60,7 @@ export async function spawnNextWorkflowTask(taskId: string): Promise<string | nu
   if (existing) return existing.id;
 
   const baseDate = task.completed_at ? new Date(task.completed_at) : new Date();
-  const dueDate = format(addDays(baseDate, nextTpl.days_from_start ?? 0), "yyyy-MM-dd");
+  const dueDate = toUTCDateString(addDays(baseDate, nextTpl.days_from_start ?? 0));
 
   const { data: created, error } = await supabase
     .from("tasks")
@@ -129,7 +141,7 @@ export async function spawnNextCollectionWorkflowTask(
   if (existing) return existing.id;
 
   const baseDate = ct.done_at ? new Date(ct.done_at) : new Date();
-  const dueDate = format(addDays(baseDate, nextTpl.days_from_start ?? 0), "yyyy-MM-dd");
+  const dueDate = toUTCDateString(addDays(baseDate, nextTpl.days_from_start ?? 0));
 
   const { data: created, error } = await supabase
     .from("collection_tasks")
diff --git a/src/routes/collections.$collectionId.tsx b/src/routes/collections.$collectionId.tsx
index 7e62441..5d0fcc4 100644
--- a/src/routes/collections.$collectionId.tsx
+++ b/src/routes/collections.$collectionId.tsx
@@ -38,7 +38,7 @@ import { CaseInvoicesTab } from "@/components/cases/invoices-tab";
 
 import { CaseLitigationTab } from "@/components/cases/litigation-tab";
 import { CaseCustomFieldsTab } from "@/components/cases/custom-fields-tab";
-import { formatDate } from "@/lib/format";
+import { formatDate, parseDateOnly } from "@/lib/format";
 import {
   ArrowLeft,
   ArrowRight,
@@ -526,7 +526,7 @@ function CollectionDetailRoute() {
                       const overdue =
                         !t.done &&
                         t.due_date &&
-                        new Date(t.due_date) < new Date(new Date().toDateString());
+                        parseDateOnly(t.due_date)! < new Date(new Date().toDateString());
                       return (
                         <div
                           key={t.id}
diff --git a/src/routes/tasks.index.tsx b/src/routes/tasks.index.tsx
index 75f1ca6..c826086 100644
--- a/src/routes/tasks.index.tsx
+++ b/src/routes/tasks.index.tsx
@@ -24,6 +24,7 @@ import { NewTaskDialog } from "@/components/tasks/new-task-dialog";
 import { ApplyWorkflowPickerDialog } from "@/components/tasks/apply-workflow-picker-dialog";
 import { cn } from "@/lib/utils";
 import { spawnNextWorkflowTask } from "@/lib/workflow-chain";
+import { parseDateOnly } from "@/lib/format";
 
 export const Route = createFileRoute("/tasks/")({
   component: TasksPage,
@@ -166,7 +167,7 @@ function TasksPage() {
         groups["No due date"].push(t);
         continue;
       }
-      const d = startOfDay(new Date(t.due_date));
+      const d = startOfDay(parseDateOnly(t.due_date)!);
       if (isBefore(d, today)) groups.Overdue.push(t);
       else if (isSameDay(d, today)) groups.Today.push(t);
       else if (isSameDay(d, tomorrow)) groups.Tomorrow.push(t);
@@ -297,7 +298,7 @@ function TasksPage() {
                       .map((p) => p.full_name || p.email);
                     let countdown: { label: string; tone: string } | null = null;
                     if (t.due_date && t.status !== "complete") {
-                      const days = differenceInCalendarDays(startOfDay(new Date(t.due_date)), startOfDay(new Date()));
+                      const days = differenceInCalendarDays(startOfDay(parseDateOnly(t.due_date)!), startOfDay(new Date()));
                       if (days < 0)
                         countdown = {
                           label: `${Math.abs(days)}d overdue`,
@@ -342,7 +343,7 @@ function TasksPage() {
                           <div className="text-xs text-right shrink-0">
                             <div className="text-muted-foreground flex items-center gap-1 justify-end">
                               <CalIcon className="h-3 w-3" />
-                              {format(new Date(t.due_date), "MMM d, yyyy")}
+                              {format(parseDateOnly(t.due_date)!, "MMM d, yyyy")}
                             </div>
                             {countdown && (
                               <div className={cn("text-[11px] font-medium", countdown.tone)}>