In the nick of time
Just in time; at the precise moment.
The English language gives us the opportunity to be 'in' many things - the doldrums, the offing, the pink; we can even be down in the dumps. With all of these expressions it is pretty easy to see what they refer to, but what or where is the 'nick of time'? It may not be immediately obvious what the nick of time is, but we do know what it means to be in it, i.e. arriving at the last propitious moment. Prior to the 16th century there was another expression used to convey that meaning - 'pudding time'. This relates to the fact that pudding was the dish served first at mediaeval mealtimes. To arrive at pudding time was to arrive at the start of the meal, just in time to eat. Pudding was then a savoury dish - a form of sausage or haggis (see also the proof is in the pudding). Pudding time is first referred to in print in John Heywood's invaluable glossary A dialogue conteinyng the nomber in effect of all the prouerbes in the Englishe tongue, 1546:
This geare comth euen in puddyng time ryghtly.
That seems a perfectly serviceable idiom, so why did the Tudors change it to 'the nick of time'? The motivation appears to be the desire to express a finer degree of timing than the vague 'around the beginning of the meal'. The nick that was being referred to was a notch or small cut and was synonymous with precision. Such notches were used on 'tally' sticks to measure or keep score. Also, during the 16th century, pudding began being used as the name of sweet dishes and they were usually served at the end of the meal. As this trend continued 'pudding time' being used to mean 'in good time' made less and less sense.
Note: the expressions 'keeping score' and 'keeping tally' derive from this and so do 'stocks' and 'shares', which refer to the splitting of such sticks (stocks) along their length and sharing the two matching halves as a record of a deal.
If someone is now said to be 'in the nick' the English would expect him to be found in prison, the Scots would picture him in the valley between two hills and Australians would imagine him to be naked. To Shakespeare and his contemporaries if someone were 'in (or at, or upon) the (very) nick' they were in the precise place at the precise time. Watches and the strings of musical instruments were adjusted to precise pre-marked nicks to keep them in proper order. Ben Jonson makes a reference to that in the play Pans Anniversary, circa 1637:
For to these, there is annexed a clock-keeper, a grave person, as Time himself, who is to see that they all keep time to a nick.
Arthur Golding gave what is likely to be the first example of the use of 'nick' in this context in his translation of Ovid's Metamorphosis, 1565:
Another thing cleane overthwart there commeth in the nicke:
The Ladie Semell great with childe by Jove as then was quicke.
The 'time' in 'the nick of time' is rather superfluous, as nick itself refers to time. The first example of the use of the phrase as we now know it comes in Arthur Day's Festivals, 1615:
Even in this nicke of time, this very, very instant.