add monthly backup frequency with multi-day selection

app/client/modules/backups/components/create-schedule-form.tsx

@@ -1,4 +1,5 @@
 import { arktypeResolver } from "@hookform/resolvers/arktype";
+
 import { useQuery } from "@tanstack/react-query";
 import { type } from "arktype";
 import { useCallback, useState } from "react";
@@ -18,6 +19,7 @@ import {
 } from "~/client/components/ui/form";
 import { Input } from "~/client/components/ui/input";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "~/client/components/ui/select";
+import { Button } from "~/client/components/ui/button";
 import { Textarea } from "~/client/components/ui/textarea";
 import { VolumeFileBrowser } from "~/client/components/volume-file-browser";
 import type { BackupSchedule, Volume } from "~/client/lib/types";
@@ -33,6 +35,7 @@ const internalFormSchema = type({
 	frequency: "string",
 	dailyTime: "string?",
 	weeklyDay: "string?",
+	monthlyDays: "string[]?",
 	keepLast: "number?",
 	keepHourly: "number?",
 	keepDaily: "number?",
@@ -78,16 +81,20 @@ const backupScheduleToFormValues = (schedule?: BackupSchedule): InternalFormValu
 	}
 
 	const parts = schedule.cronExpression.split(" ");
-	const [minutePart, hourPart, , , dayOfWeekPart] = parts;
+	const [minutePart, hourPart, dayOfMonthPart, , dayOfWeekPart] = parts;
 
 	const isHourly = hourPart === "*";
-	const isDaily = !isHourly && dayOfWeekPart === "*";
+	const isMonthly = !isHourly && dayOfMonthPart !== "*" && dayOfWeekPart === "*";
-	const frequency = isHourly ? "hourly" : isDaily ? "daily" : "weekly";
+	const isDaily = !isHourly && dayOfMonthPart === "*" && dayOfWeekPart === "*";
+
+	const frequency = isHourly ? "hourly" : isMonthly ? "monthly" : isDaily ? "daily" : "weekly";
 
 	const dailyTime = isHourly ? undefined : `${hourPart.padStart(2, "0")}:${minutePart.padStart(2, "0")}`;
 
 	const weeklyDay = frequency === "weekly" ? dayOfWeekPart : undefined;
 	
+	const monthlyDays = isMonthly ? dayOfMonthPart.split(",") : undefined; 
+
 	const patterns = schedule.includePatterns || [];
 	const isGlobPattern = (p: string) => /[*?[\]]/.test(p);
 	const fileBrowserPaths = patterns.filter((p) => !isGlobPattern(p));
@@ -96,7 +103,8 @@ const backupScheduleToFormValues = (schedule?: BackupSchedule): InternalFormValu
 	return {
 		name: schedule.name,
 		repositoryId: schedule.repositoryId,
-		frequency,
+        frequency,
+        monthlyDays, 
 		dailyTime,
 		weeklyDay,
 		includePatterns: fileBrowserPaths.length > 0 ? fileBrowserPaths : undefined,
@@ -249,6 +257,7 @@ export const CreateScheduleForm = ({ initialValues, formId, onSubmit, volume }:
 													<SelectItem value="hourly">Hourly</SelectItem>
 													<SelectItem value="daily">Daily</SelectItem>
 													<SelectItem value="weekly">Weekly</SelectItem>
+													<SelectItem value="monthly">Monthly</SelectItem>
 												</SelectContent>
 											</Select>
 										</FormControl>
@@ -302,6 +311,42 @@ export const CreateScheduleForm = ({ initialValues, formId, onSubmit, volume }:
 									)}
 								/>
 							)}
+							{frequency === "monthly" && (
+                                <FormField
+                                    control={form.control}
+                                    name="monthlyDays"
+                                    render={({ field }) => (
+                                        <FormItem className="md:col-span-2">
+                                            <FormLabel>Days of the month</FormLabel>
+                                            <FormControl>
+                                                <div className="grid grid-cols-7 gap-4 w-max">
+                                                    {Array.from({ length: 31 }, (_, i) => {
+                                                        const day = (i + 1).toString();
+                                                        const isSelected = field.value?.includes(day);
+                                                        return (
+                                                            <Button
+                                                                type="button"
+                                                                key={day}
+                                                                variant={isSelected ? "primary" : "secondary"}
+                                                                size="icon"
+                                                                onClick={() => {
+                                                                    const current = field.value || [];
+                                                                    const next = isSelected ? current.filter((d) => d !== day) : [...current, day];
+                                                                    field.onChange(next);
+                                                                }}
+                                                            >
+                                                                {day}
+                                                            </Button>
+                                                        );
+                                                    })}
+                                                </div>
+                                            </FormControl>
+                                            <FormDescription>Select one or more days when the backup should run.</FormDescription>
+                                            <FormMessage />
+                                        </FormItem>
+                                    )}
+                                />
+                            )}
 						</CardContent>
 					</Card>
 

app/client/modules/backups/routes/backup-details.tsx

@@ -141,7 +141,7 @@ export default function ScheduleDetailsPage({ params, loaderData }: Route.Compon
 	const handleSubmit = (formValues: BackupScheduleFormValues) => {
 		if (!schedule) return;
 
-		const cronExpression = getCronExpression(formValues.frequency, formValues.dailyTime, formValues.weeklyDay);
+		const cronExpression = getCronExpression(formValues.frequency, formValues.dailyTime, formValues.weeklyDay, formValues.monthlyDays);
 
 		const retentionPolicy: Record<string, number> = {};
 		if (formValues.keepLast) retentionPolicy.keepLast = formValues.keepLast;

app/client/modules/backups/routes/create-backup.tsx

@@ -71,7 +71,7 @@ export default function CreateBackup({ loaderData }: Route.ComponentProps) {
 	const handleSubmit = (formValues: BackupScheduleFormValues) => {
 		if (!selectedVolumeId) return;
 
-		const cronExpression = getCronExpression(formValues.frequency, formValues.dailyTime, formValues.weeklyDay);
+		const cronExpression = getCronExpression(formValues.frequency, formValues.dailyTime, formValues.weeklyDay, formValues.monthlyDays);
 
 		const retentionPolicy: Record<string, number> = {};
 		if (formValues.keepLast) retentionPolicy.keepLast = formValues.keepLast;

app/utils/utils.ts

@@ -1,6 +1,6 @@
 import { intervalToDuration } from "date-fns";
 
-export const getCronExpression = (frequency: string, dailyTime?: string, weeklyDay?: string): string => {
+export const getCronExpression = (frequency: string, dailyTime?: string, weeklyDay?: string,monthlyDays?: string[]): string => {
 	if (frequency === "hourly") {
 		return "0 * * * *";
 	}
@@ -15,6 +15,12 @@ export const getCronExpression = (frequency: string, dailyTime?: string, weeklyD
 		return `${minutes} ${hours} * * *`;
 	}
 	
+	if (frequency === "monthly") {
+        const sortedDays = (monthlyDays || []).map(Number).sort((a, b) => a - b);
+        const days = sortedDays.length > 0 ? sortedDays.join(",") : "1";
+        return `${minutes} ${hours} ${days} * *`;
+    }
+
 	return `${minutes} ${hours} * * ${weeklyDay ?? "0"}`;
 };