Months of rumours will be put to the test as the season of wheeling and dealing begins.
It might seem odd that the month in which so little football is played could also be one of the most important but that's Scottish football for you.
The January transfer window will give clubs across Scotland the chance to oil some squeaky wheels and maybe even add a few upgrades to their current squads.
With Celtic and Rangers both storming through to the later stages of the Europa League, all while embroiled in one of the tightest domestic battles in years, a good winter break could prove pivotal to either Glasgow side's season.
Their Edinburgh rivals have new gaffers in charge while perpetual also-rans Aberdeen will look to remain strong enough to keep powering on.
Half the season has whizzed by and every team now has a clearer idea of where their weaknesses lie and which areas need re-enforced this January.
Here’s a quick guide to how they can go about doing so during January 2020's transfer window.
When does the transfer window open?
For Scottish clubs, the January transfer window opens for business as soon as the New Year begins, on Wednesday 1 January.
The same is true for teams across the border in England, as well as for those in France, Germany and China.
Clubs in Spain and Italy delay their window by a day, with the deals beginning on Thursday 2 January instead.
For teams based in Portugal, the transfer period doesn’t begin until 3 January, while those in Russia will be waiting all the way to 22 January.
What are the rules?
First of all, players who are signed on 1 or 2 January will not be eligible to play in that week’s games.
However, after that teams are free to alter their registered squads throughout the January transfer period, meaning any other arrivals can take to the field as soon as they turn up.
The English window closes an hour earlier than the Scottish one, however deals still being hammered out when the window snaps shut can still be completed. Between 9pm and 11pm, clubs can submit the details of any ongoing negotiations using a Deal Sheet, giving them until midnight that day to get the deal finished.
After the window closes, no more transfers can be made between clubs. Previously, the Emergency Loan rule allowed sides to make loan deals outwith the transfer period to cover unexpected gaps (like serious injuries) but this was scrapped in 2016.
Free agents – players not contracted to any club – can still sign for a team at any point in the season.
When does it close?
The Scottish transfer window will close at midnight on 31 January, giving clubs until the very end of the day to get their business done.
For English sides, the January transfer window slams shut at 11pm on the same day. However, as previously mentioned, they can take until midnight to wrap up any deals that have already gotten underway.
The midnight deadline holds true for teams in France, Germany, Italy and Spain. This means that the five elite divisions of European football will all call a halt to trading at the same time.
Portuguese clubs have until the end of 1 February to get their deals over the line, while the Russian window runs on until 22 February, and the Chinese one remains open until 27 February.
This is why rumours of lucrative moves to China often persist long after the European transfer season has ended.