What does “конь не валялся” Russian expression mean?

To be honest, unfortunately, in my everyday life, I often use this phrase.  I think many of you too.  Everyone who is familiar with the term procrastination, also often use this strange Russian idiom.

(Procrastination is the practice of carrying out less urgent tasks in preference to more urgent ones, or doing more pleasurable things in place of less pleasurable )

Every time when I need to write an article similar to this or a report or do something important, time moves on and “my horse still did not lie  about/wallowed”

What does “конь не валялся” Russian expression mean?

Literally speaking, конь –means “horse”  (male horse)

The verb “валяться” is one of my favorites.  Imagine Sunday morning: you woke up, but you are still in the bed, you took the laptop or a book and stay in the bed reading or watching a film and enjoying the morning. You slug-a-bed.   In the meaning of this verb you can lie everywhere  (on the grass, on the carpet, on the sofa etc) and enjoy you life.  You can something in combining with lying. You can just lie.  

Russian-English dictionary define this Russian verb as the following English ones:

wallow, loll, lie about, be rolled, lounge around, slug

Russian expression "здесь ещё конь не валялся" denotes that the work you have to do or preparation for this work (diploma, article etc) has not yet begun. 

Usually we say this expression when you think about the deadline.

Скоро сдавать годовой отчёт, уже июнь, а у меня еще конь не валялся.

It’s already June, I have to submit an annual report soon, but I still haven't even  started

History

The story of the origin of this Russian expression is still unclear.

In the famous Dal dictionary this expression is given without explaining etymology.

 They say that this Russian phrase dates back to the peasant traditions: they give the horse to wallow before tackling up, so a horse is less tired during a work.

Saying "конь не валялся" ( a horse didn’t  wallow) means that the grass is still not touched. This is the association with untouched grass like a blank sheet of paper and that means that the work had not even begun.

Examples:

1) Надо писать диплом ( статью, отчет) , а у меня еще и конь не валялся ( Я)

2) «А Фауст был ученый, а не аспирант. Можно сказать, академик. А у вас, Ричард, еще конь не валялся. Все рассуждаете. Так вы и останетесь вечнозеленым деревом» 
(Д. Гранин).

3) Авось проснулся Меркулов... но у Меркулова, как говорится, и конь еще не валялся.  (Мельников)

Do you know any English/French analogue?

If you find a mistake in my text or if you think that some sentences or phrases that can be said more clearly - let me know. Thank you