A day trip from Delhi to Haridwar and Rishikesh can be an exciting adventure. Both Haridwar and Rishikesh are located in the state of Uttarakhand and are known for their spiritual significance and natural beauty. Here's a suggested itinerary for a same-day trip from Delhi:

1. Start Early Depart from Delhi as early as possible, ideally before sunrise, to make the most of your day.

2. Travel: The distance from Delhi to Haridwar is approximately 220 kilometers, and it takes around 5-6 hours to reach by car or bus. Plan your transportation accordingly. You can also consider taking a train from Delhi to Haridwar, which is a popular option and can save time. Make sure to book your transportation tickets in advance.

3. Haridwar: Upon reaching Haridwar, you can visit the following places and participate in activities:
   Har Ki Pauri: This is a famous ghat where the Ganges Aarti takes place. It's a must-visit to witness the evening Aarti ceremony.
   Mansa Devi Temple: You can take a cable car ride to reach the Mansa Devi Temple, which offers panoramic views of the city.
   Chandi Devi Temple: Another important temple, Chandi Devi can be reached by a cable car as well.

4. Lunch: Enjoy a delicious North Indian meal at a local restaurant or dhaba.

5. Rishikesh: After spending the morning and early afternoon in Haridwar, head to Rishikesh, which is around 20-30 minutes away by car.

6. Rishikesh Activities
   Laxman Jhula and Ram Jhula Take a walk on these iconic suspension bridges and explore the surrounding markets.
   Triveni Ghat: Visit this ghat for a holy dip in the Ganges or simply to witness the evening Aarti.
   Visit Ashrams: Rishikesh is famous for its yoga and meditation centers. You can explore some of the ashrams in the area.

7. Adventure Activities: If you're interested in adventure sports, you can try activities like white-water rafting, trekking, or camping in the vicinity of Rishikesh. These activities may require more time, so plan accordingly.

8. Evening and Sunset: Spend some time by the riverbank, relax, and enjoy the peaceful ambiance of Rishikesh.

9. Return to Delhi: Depart for Delhi in the evening to avoid late-night travel.

Please note that this is a tightly packed day, and you might not be able to explore everything in detail. Adjust the itinerary according to your interests and available time. Additionally, make sure to check the latest travel advisories, transportation options, and entry requirements, as these can change.