Five local authorities across the UK see their populations soar by more than 100,000 during a workday, but the real explosion is seen in the City of London.
During the day, the gains from usually resident to workday populations see a 56 fold increase in the City, according to 2011 Census data. The second greatest rise in the UK is seen in Westminster, which witnesses a three fold increase during the working day.
The only other areas to see their populations increase so heavily (by over 100,000) during the working week are Camden, Tower Hamlets and Manchester.
Areas seeing the largest decreases in workday population compared to usually resident population include many London boroughs. Eight of the twenty local authorities that see the biggest falls are on the edges of the capital.
There are also striking differences in the gender of working day populations across London.
North Warwickshire sees its workday gender ratio change most dramatically. During the working week this increases from 99 males per 100 females to 133 males per 100 females, as male workers commute to the area to work in the region's automotive and mining industries.