Paint it Black

[Sundae]

According to our media it was yesterday, so chin up! You're through the worst

From what I remember it's the Monday of the last week in January rather than a specific date. It also takes into account the approximate date of pay for people on monthly salaries, the temperature (coldest time of the year in the UK) and those good old Monday morning back-to-work blues.

Edited to add the actual formula:
Arnall's worst day "formula" is ([W + (D-d)] x TQ) ÷ (M x NA). (W: weather, D: debt, d: money due in January pay, T: time elapsed since Christmas, Q: time since failed New Year's resolutions to quit smoking, drinking etc, M: general motivational levels, NA: the need to take action.)