Correct method to perform Mahashivaratri Vrata. How to celebrate Mahashivaratri?

Mahashivaratri is celebrated on the Chaturdashi Tithi of the Krishna Paksha of Magha month (as per Amanta calendar) and Phalguna month (as per Purnimanta calendar). Irrespective of which calendar you follow, Mahashivaratri is celebrated on the same day. 

1. You have to be awake during the entire night. You should not be lying down. You can either sit and meditate or do bhajan. Even Nrtya seva or Vadya Seva are recommended as Mahadev is very fond of dance (Nrtya or Vadya Priya).

2. You will have to perform four Pujas during the entire night, as per timings below. If you cannot do puja 4 times, then at least perform the Nishith Kaal Puja. Why puja is done four times? Every night is divided into 4 prahars (parts). Doing Puja four times, stimulates and enlightens our awareness and consciousness during the four different prahars of the night.

Ratri First Prahar Puja Time - 06:40 PM to 09:42 PM,

Ratri Second Prahar Puja Time - 09:42 PM to 12:45 AM, Feb 27,

Ratri Third Prahar Puja Time - 12:45 AM to 03:48 AM, Feb 27,

Ratri Fourth Prahar Puja Time - 03:48 AM to 06:50 AM, Feb 27

Or just do one 
Nishith Kaal Puja - 12:21 AM to 01:09 AM, Feb 27

3. You have to fast during the entire tithi of Chaturdashi (from 11:08 AM on Feb 26, 2025 to 08:54 AM on Feb 27, 2025). You may consume water but staunch devotees who have performed the Mahashivaratri vrata a few times will even forego water. If you are not medically fit, then you may eat some fruits or have very light meals. But the most important point of this vrata is to fast for the entire Chaturdashi. And strictly speaking, fasting means not consuming food of any kind and this has been validated clearly in the Puranas and other scriptures. So if you healthy and fit, then you can definitely give this a try.

4. You will need to have just one meal before the Mahashivaratri. So, your only meal will be at noon on Wednesday (Trayodashi). Either breakfast or lunch in the afternoon.

5. On Feb 26th, Wednesday you will need to take bath and take a Sankalpa in the morning.

“I, <your name>, from <gotra>, born under <rashi> <nakshatra>, am undertaking this Mahashivaratri vrata on this Chaturdashi tithi. I vow to not consume any food until the end of the Chaturdashi tithi and will break my fast only after that. I am doing this to receive and attain the grace and blessing of Mahadev. Please give me strength to complete this successfully. If if have inadvertently or unknowingly done any mistake then please forgive me.”

6. Then visit any nearby Shiva temple and do Jala Abhisheka on the Linga and offer Bilva leaves. If you have Shiva Linga at home then you can do Abhishekam of the Linga at home itself. Just water is enough for Abhishekam as per scriptures for Mahashivaratri, but you can also offer other dravya like honey, curd, milk etc based on your best abilities and devotion (Yathashakthi).

7. In the evening you will need to take bath and only then perform the puja in the above given timings. While doing puja you can chant Rudram (Namakam and Chamakam) and/or Rudrashtakam and/or Bilvashtakam. Or if you do not know any stotra of Shiva then you can simply chant 'ॐ नमः शिवाय' as per your abilities.

Scriptures stress a lot upon on two things -

1. Being awake the entire night and fasting for the entire Chaturdashi. 
2. Offering Bilva and Jala Abhisheka to the Shiva Linga (even mentally).

So, if you want it to be successful in your Vrata, then you have meet both these conditions. I can vouch from my personal experience that there is no better tapasya in Kali Yuga than sacrificing food. Even Mahabharata, clearly mentions the merits of complete fasting in Anusasana Parva.

I wish you all the best and may Mahadev shower His grace upon everyone.
Happy Mahashivaratri!