diff --git a/src/templates/__tests__/generate.test.ts b/src/templates/__tests__/generate.test.ts
new file mode 100644
index 0000000..42fe8a2
--- /dev/null
+++ b/src/templates/__tests__/generate.test.ts
@@ -0,0 +1,55 @@
+import {
+    assertStringIncludes,
+} from 'https://deno.land/std@0.224.0/assert/mod.ts';
+import { TimerOptions } from '../../types/mod.ts';
+import { generateUnits } from '../unit-generator.ts';
+
+Deno.test('generateUnits erzeugt Basis-Service und Timer korrekt', () => {
+    const opts: TimerOptions = {
+        exec: '/usr/bin/my-script',
+        calendar: 'daily',
+    };
+    const { serviceUnit, timerUnit } = generateUnits('myjob', opts);
+
+    assertStringIncludes(serviceUnit, 'ExecStart=/usr/bin/my-script');
+    assertStringIncludes(timerUnit, 'OnCalendar=daily');
+    assertStringIncludes(timerUnit, '[Install]');
+});
+
+Deno.test('generateUnits setzt Beschreibung aus Option', () => {
+    const opts: TimerOptions = {
+        exec: '/bin/true',
+        calendar: 'daily',
+        description: 'Meine Unit',
+    };
+    const { serviceUnit } = generateUnits('job', opts);
+
+    assertStringIncludes(serviceUnit, 'Description=Meine Unit');
+});
+
+Deno.test('generateUnits berücksichtigt after=', () => {
+    const opts: TimerOptions = {
+        exec: '/bin/true',
+        calendar: 'daily',
+        after: ['network-online.target', 'docker.service'],
+    };
+    const { serviceUnit } = generateUnits('job', opts);
+
+    assertStringIncludes(serviceUnit, 'After=network-online.target');
+    assertStringIncludes(serviceUnit, 'After=docker.service');
+});
+
+Deno.test('generateUnits berücksichtigt environment und logfile', () => {
+    const opts: TimerOptions = {
+        exec: '/bin/true',
+        calendar: 'daily',
+        environment: ['FOO=bar', 'DEBUG=1'],
+        logfile: '/var/log/job.log',
+    };
+    const { serviceUnit } = generateUnits('job', opts);
+
+    assertStringIncludes(serviceUnit, 'Environment=FOO=bar');
+    assertStringIncludes(serviceUnit, 'Environment=DEBUG=1');
+    assertStringIncludes(serviceUnit, 'StandardOutput=append:/var/log/job.log');
+    assertStringIncludes(serviceUnit, 'StandardError=append:/var/log/job.log');
+});
diff --git a/src/templates/unit-generator.ts b/src/templates/unit-generator.ts
new file mode 100644
index 0000000..8e6a0a6
--- /dev/null
+++ b/src/templates/unit-generator.ts
@@ -0,0 +1,63 @@
+import { TimerOptions } from '../types/mod.ts';
+import { deriveNameFromExec, writeUnitFiles } from '../utils/mod.ts';
+
+export async function generateUnitFiles(options: TimerOptions): Promise<void> {
+    const name = options.name || deriveNameFromExec(options.exec);
+
+    const { serviceUnit, timerUnit } = generateUnits(name, options);
+
+    if (options.dryRun) {
+        console.log(`===== ${name}.service =====`);
+        console.log(serviceUnit);
+        console.log(`\n===== ${name}.timer =====`);
+        console.log(timerUnit);
+    } else {
+        const { servicePath, timerPath } = await writeUnitFiles(
+            name,
+            serviceUnit,
+            timerUnit,
+            options,
+        );
+        console.log(`Service unit written to: ${servicePath}`);
+        console.log(`Timer unit written to: ${timerPath}`);
+    }
+}
+
+export function generateUnits(name: string, options: TimerOptions): {
+    serviceUnit: string;
+    timerUnit: string;
+} {
+    const unitParts = [
+        `[Unit]`,
+        `Description=${options.description ?? name}`,
+        ...(options.after?.map((a) => `After=${a}`) ?? []),
+        ``,
+        `[Service]`,
+        `Type=oneshot`,
+        `ExecStart=${options.exec}`,
+        ...(options.environment?.map((e) => `Environment=${e}`) ?? []),
+    ];
+
+    if (options.logfile) {
+        unitParts.push(`StandardOutput=append:${options.logfile}`);
+        unitParts.push(`StandardError=append:${options.logfile}`);
+    }
+
+    const serviceUnit = unitParts.join('\n');
+
+    const timerParts = [
+        `[Unit]`,
+        `Description=Timer for ${name}`,
+        ``,
+        `[Timer]`,
+        `OnCalendar=${options.calendar}`,
+        `Persistent=true`,
+        ``,
+        `[Install]`,
+        `WantedBy=timers.target`,
+    ];
+
+    const timerUnit = timerParts.join('\n');
+
+    return { serviceUnit, timerUnit };
+}