Zimbabwe has made former president Robert Mugabe's birthday a public holiday, a state daily reported on Monday, nearly a week after the long-time ruler stepped down.

"It is hereby declared that February 21 of every year henceforth shall be a public holiday to be known as the Robert Mugabe National Youth Day," The Herald newspaper reported, citing a government gazette.

The move follows intense lobbying by the ruling Zanu-PF party's youth league and came weeks after the country's biggest airport was renamed after the veteran politician who ruled Zimbabwe for nearly 40 years.

His tenure withstood repeated claims of hanging on to power through brutal repression of dissent, election rigging and corruption, until concerted pressure from the military finally forced to quit.

Parliament had begun proceedings to impeach Mugabe for allowing his wife and a coterie of followers to "capture" the ruling party.

The 93-year-old was replaced by Emmerson Mnangagwa, who was vice president until Mugabe fired him just weeks ago.

The declaration of his birthday as a holiday is the latest of many accolades.

Zimbabwe's school of intelligence was named after him while a $1bn Robert Mugabe university is also in the works.

Several buildings and roads across the country are also named after him.

Zimbabwe's opposition accuse Mugabe of spending scarce money on wasteful projects despite the country being forced to grapple with poverty and an unemployment rate of more than 90%.