From captured Russian documents during the first week, reported in Forbes and other news, the President of Belarus letting it slip, Russia planned for a fifteen day war. The goal was to capture Kyiv and key cities and expected the population to welcome them.
Forbes attributed the alleged documents directly to the Facebook page of the "Ukranian's military's Operational Group East."
The Forbes article directly contradicts the conclusion that the alleged documents published by the Ukranians on Facebook, if real, would mean that operations were to be completed by March 6.
https://twitter.com/Forbes/status/1499399221023178754
Forbes @Forbes. Mar 3
The Ukrainian’s military’s Operational Group East has posted to its Facebook page what it says are invasion plans captured from Russia’s 810th Naval Infantry Brigade
Alleged Captured Documents Imply Ukraine Invasion Planned In JanuarySebastien Roblin, Contributor
I cover international security, conflict, history and aviation.Mar 3, 2022,03:50am EST
The Ukrainian’s military’s Operational Group East has posted to its Facebook page what it says are invasion plans captured from Russia’s 810th Naval Infantry Brigade.
The documents, which seemingly were stamped January 18, 2022, establish call signs and radio frequencies for operations for 15 days between February 20 and March 6, and include maps detailing plans to seize the city of Melitopol. As it happens, amphibious landing ships of the Black Sea Fleet did leave port on February 20, though combat operations did not begin until February 24.
Melitopol, which has a population of around 150,000, was swiftly occupied by Russian troops advancing out of the Crimean peninsula, obviating the need for any amphibious landing operations. However, fighting continued to rock the city until this Tuesday, and local residents are actively protesting the Russian occupation.
The Ukrainian military’s Operational Group East posted the alleged documents to their Facebook page on Wednesday, introduced as follows:
Thanks to the successful actions of one of the units of the Ukrainian Armed Forces, the Russian occupiers are losing not only their equipment and manpower. In a panic, they are leaving behind secret documents.
[...]
Of course, the existence of changing daily call signs for a two-week stretch doesn’t confirm that combat operations were planned during that period when the documents were signed. Nor does the final date reading March 6 necessarily mean that any combat operations were expected to complete then—it may simply have been the end of a two-week planning cycle.
The plan did not start on time, which weas correctly cited in your post. That is not a contradiction, that is "no battle plan survives contact with the enemy".
#2, The Facebook post where the Russian documents are posted is https://www.facebook.com/100069073844828/posts/267699898875803/?d=n, which is by the Міністерство оборони України, https://www.facebook.com/MinistryofDefence.UA, the official Facebook page of the Ministry of Defense of Ukraine.
The purported captured Russian invasion plans were posted on the Ministry of Defense of Ukraine Facebook account.
#3. The 810th is under Operational Group East of the Ukrainian armed forces. They claim to have captured some documents, that were posted to the Ukrainian MOD Facebook page. Forbes put out a tweet that was not clearly written to link to their story.
That is all there is to this, and it is simple enough to figure this out by going through the links.
#4. Sebastien Roblin is too experienced a writer to make careless mistakes. His story links to the Facebook page with the documents, not Forbes's tweet on his story.