

Essentially, cancelling public holidays will in short term add some slave labourto the company, which in turn maybe add more profits, more b2b economical activity, and if France has any decent corporate tax and not too many loopholes, some money will go into budget to be allocated to usual overspending that got you into this place, and none to repay debts.
Tldr: you’re being screwed over, go protest, or ask for raises when this actually occurs.
Actually, it’s enough for building the Pentagon for its original budget (43million in 1941) adjusted to inflation: 767 million. Though building materials and labour are starkly cheaper now, so maybe 2 or 3 Pentagons