Every ‘then’, however, is, as such, a ‘then, when …’; every ‘on that former occasion’ is an ‘on that former occasion, when …’; every ‘now’ is a ‘now that …’. The ‘now’, the ‘then’, and the ‘on that former occasion’ thus have a seemingly obvious relational structure which we call “datability” [Datierbarkeit]. Whether this DATING is factically done with respect to a ‘date’ on the calendar, must still be completely disregarded. Evenwithout ‘dates’ of this sort, the ‘now’, the ‘then’, and the ‘on that former occasion’ have been dated more or less definitely. And even if the DATING is not made more definite, this does not mean that the structure of datability is missing or that it is just a matter of chance. BTMR §79
The fact that the structure of datability belongs essentially to what has been interpreted with the ‘now’, the ‘then’, and the ‘on that former occasion’, becomes the most elemental proof that what has thus been interpreted has originated in the temporality which interprets itself. When we say ‘now’, we always understand a ‘now that so and so …’ though we do not say all this. Why? Because the “now” interprets a making-present of entities. In the ‘now that …’ lies the ecstatical character of the Present. The datability of the ‘now’, the ‘then’, and the ‘on that former occasion’, reflects the ecstatical constitution of temporality, and is therefore essential for the time itself that has been expressed. The structure of the datability of the ‘now’, the ‘then’, and the ‘on that former occasion’, is evidence that these, stemming from temporality, are themselves time. The interpretative expressing of the ‘now’, the ‘then’, and the ‘on that former occasion’, is the most primordial way of assigning a time. In the ecstatical unity of temporality – which gets understood along with datability, but unthematically and without being recognizable as such – Dasein has already been disclosed to itself as Being-in-the-world, and entities within-the-world have been discovered along with it; because of this, interpreted time has’ already been given a DATING in terms of those entities which are encountered in the disclosedness of the “there”: “now that – the door slams”; “now that – my book is missing”, and so forth. BTMR §79
As something disclosed, Dasein exists factically in the way of Being with Others. It maintains itself in an intelligibility which is public and average. When the ‘now that …’ and the ‘then when …’ have been interpreted and expressed in our everyday Being with one another, they will be understood in principle, even though their DATING is unequivocal only within certain limits. In the ‘most intimate’ Being-with-one-another of several people, they can say ‘now’ and say it ‘together’, though each of them gives a different date to the ‘now’ which he is saying: “now that this or that has come to pass …” The ‘now’ which anyone expresses is always said in the publicness of Being-in-the-world with one another. Thus the time [SZ:411] which any Dasein has currently interpreted and expressed has as such already been given a public character on the basis of that Dasein’s ecstatical Being-in-the-world. In so far, then, as everyday concern understands itself in terms of the ‘world’ of its concern and takes its ‘time’, it does not know this ‘time’ as its own, but concernfully utilizes the time which ‘there is’ [“es gibt”] – the time with which “they” reckon. Indeed the publicness of ‘time’ is all the more compelling, the more explicitly factical Dasein concerns itself with time in specifically taking it into its reckoning. BTMR §79
Although one can concern oneself with time in the manner which we have characterized – namely, by DATING in terms of environmental events – this always happens basically within the horizon of that kind of concern with time which we know as astronomical and calendrical time-reckoning. Such reckoning does not occur by accident, but has its existential-ontological necessity in the basic state of Dasein as care. Because it is essential to Dasein that it exists fallingly as something thrown, it interprets its time concernfully by way of time-reckoning. In this, the ‘real’ making-public of time gets temporalized, so that we must say that Dasein’s thrownness is the reason why ‘there is’ time publicly. If we are to demonstrate that public time has its source in factical temporality, and if we are to assure ourselves that this demonstration is as intelligible as possible, the time which has been interpreted in the temporality of concern must first be characterized, [SZ:412] if only in order to make clear that the essence of concern with time does not lie in the application of numerical procedures in DATING. Thus in time-reckoning, what is decisive from an existential-ontological standpoint is not to be seen in the quantification of time but must be conceived more primordially in terms of the temporality of the Dasein which reckons with time. BTMR §80
Dasein awaits with circumspective concern the possibility of sight, and it understands itself in terms of its daily work; in thus awaiting and understanding, it gives its time with the ‘then, when it dawns …’ The ‘then’ with which Dasein concerns itself gets dated in terms of something which is connected with getting bright, and which is connected with it in the closest kind of environmental involvement – namely, the rising of the sun. “Then, when the sun rises, it is time for so and so.” Thus Dasein dates the time which it must take, and dates it in terms of something it encounters within the world and within the horizon of its abandonment to the world – in terms of something encountered as having a distinctive involvement for its circumspective potentiality-for-Being-in-the-world. Concern makes use of the ‘Being-ready-to-hand’ of the sun, which sheds forth light and warmth. The sun dates the time which is interpreted in concern. In terms of this DATING arises the ‘most natural’ measure of time – the day. [SZ:413] BTMR §80
And because the temporality of that Dasein which must take its time is finite, its days are already numbered. Concernful awaiting takes precaution to define the ‘thens’ with which it is to concern itself – that is, to divide up the day. And the ‘during-the-daytime’ makes this possible. This dividing-up, in turn, is done with regard to that by which time is dated – the journeying sun. Sunset and midday, like the sunrise itself, are distinctive ‘places’ which this heavenly body occupies. Its regularly recurring passage is something which Dasein, as thrown into the world and giving itself time temporalizingly, takes into its reckoning. Dasein historizes from day to day by reason of its way of interpreting time by DATING it – a way which is adumbrated in its thrownness into the “there”. BTMR §80
This DATING of things in terms of the heavenly body which sheds forth light and warmth, and in terms of its distinctive ‘places’ in the sky, is a way of assigning time which can be done in our Being with one another ‘under the same sky’, and which can be done for ‘Everyman’ at any time in the same way, so that within certain limits everyone is proximally agreed upon it. That by which things are thus dated is available environmentally and yet not restricted to the world of equipment with which one currently concerns oneself. It is rather the case that in the world the environing Nature and the public environment are always discovered along with it. This public DATING, in which everyone assigns himself his time, is one which everyone can ‘reckon’ on simultaneously; it uses a publicly available measure. This DATING reckons with time in the sense of a measuring of time; and such measuring requires something by which time is to be measured – namely, a clock. This implies that along with the temporality of Dasein as thrown, abandoned to the ‘world’, and giving itself time, something like a ‘clock’ is also discovered – that is, something ready-to-hand which in its regular recurrence has become accessible in one’s making present awaitingly. The Being which has been thrown and is alongside the ready-to-hand is grounded in temporality. Temporality is the reason for the clock. As the condition for the possibility that a clock is factically necessary, temporality is likewise the condition for its discoverability. For while the course of the sun is encountered along with the discoveredness of entities within-the-world, it is only by making it present in awaitingly retaining, and by doing so in a way which interprets itself, that DATING in terms of what is ready-to-hand environmentally in a public way is made possible and is also required. BTMR §80
When the ‘then’ which interprets itself in concernful awaiting gets dated, this DATING includes some such statement as “then – when it dawns – it is time for one’s daily work”. The time which is interpreted in concern is already understood as a time for something. The current ‘now that so and so …’ is as such either appropriate or inappropriate. Not only is the ‘now’ (and so too any mode of interpreted time) a ‘now that …’ which is essentially datable; but as such it has essentially, at the same time, the structure of appropriateness or inappropriateness. Time which has been interpreted has by its very nature the character of ‘the time for something’ or ‘the wrong time for something’. When concern makes present by awaiting and retaining, time is understood in relation to a “for-which”; and this in turn is ultimately tied up with a “for-the-sake-of-which” of Dasein’s potentiality-for-Being. With this “in-order-to” relation, the time which has been made public makes manifest that structure with which we have earlier become acquainted as significance, and which constitutes the worldhood of the world. As ‘the time for something’, the time which has been made public has essentially a world-character. Hence the time which makes itself public in the temporalizing of temporality is what we designate as “world-time”. And we designate it thus not because it is presentat-hand as an entity within-the-world (which it can never be), but because it belongs to the world [zur Welt] in the sense which we have Interpreted existential-ontologically. In the following pages we must show how the essential relations of the world-structure (the ‘in-order-to’, for example) are connected with public time (the ‘then, when …’, for example) by reason of the ecstatico-horizonal constitution of temporality. Only now, in any case, can the time with which we concern ourselves be completely characterized as to its structure: it is datable, spanned, and public; and as having this structure, it belongs to the world itself. Every ‘now’, for instance, which is expressed in a natural everyday manner, has this kind of structure, and is understood as such, though pre-conceptually and unthematically, when Dasein concernfully allows itself time. [SZ:415] BTMR §80
Comparison shows that for the ‘advanced’ Dasein the day and the presence of sunlight no longer have such a special function as they have for the ‘primitive’ Dasein on which our analysis of ‘natural’ time-reckoning has been based; for the ‘advanced’ Dasein has the ‘advantage’ of even being able to turn night into day. Similarly we no longer need to glance explicitly and immediately at the sun and its position to ascertain the time. The manufacture and use of measuring-equipment of one’s own permits one to read off the time directly by a clock produced especially for this purpose. The “what o’clock is it?” is the ‘what time is it?’ Because the clock – in the sense of that which makes possible a public way of time-reckoning – must be regulated by the ‘natural’ clock, even the use of clocks as equipment is based upon Dasein’s temporality, which, with the disclosedness of the “there”, first makes possible a’DATING of the time with which we concern ourselves; this is a fact, even if it is covered up when the time is read off. Our understanding of the natural clock develops with the advancing discovery of Nature, and instructs us as to new possibilities for a kind of time-measurement which is relatively independent of the day and of any explicit observation of the sky. BTMR §80
Saying “now”, however, is the discursive Articulation of a making-present which temporalizes itself in a unity with a retentive awaiting. The DATING which is performed when one uses a clock, turns out to be a distinctive way in which something present-at-hand is made present. DATING does not simply relate to something present-at-hand; this kind of relating has itself the character of measuring. Of course the number which we get by measuring can be read off immediately. But this implies that when a [SZ:417] stretch is to be measured, we understand that our standard is, in a way, contained in it; that is, we determine the frequency of its presence in that stretch. Measuring is constituted temporally when a standard which has presence is made present in a stretch which has presence. The idea of a standard implies unchangingness; this means that for everyone at any time the standard, in its stability, must be present-at-hand. When the time with which one concerns oneself is dated by measuring, one interprets it by looking at something present-at-hand and making it present – something which would not become accessible as a standard or as something measured except by our making it present in this distinctive manner. Because the making-present of something having presence has a special priority in DATING by measuring, the measurement in which one reads off the time by the clock also expresses itself with special emphasis in the “now”. Thus when time is measured, it is made public in such a way that it is encountered on each occasion and at any time for everyone as ‘now and now and now’. This time which is ‘universally’ accessible in clocks is something that we come across as a present-at-hand multiplicity of “nows”, so to speak, though the measuring of time is not directed thematically towards time as such. BTMR §80
The temporality of factical Being-in-the-world is what primordially makes the disclosure of space possible; and in each case spatial Dasein has – out of a “yonder” which has been discovered – allotted itself a “here” which is of the character of Dasein. Because of all this the time with which Dasein concerns itself in its temporality is, as regards its datability, always bound up with some location of that Dasein. Time itself does not get linked to a location; but temporality is the condition for the possibility that DATING may be bound up with the spatially-local in such a way that this may be binding for everyone as a measure. Time does not first get coupled with space; but the ‘space’ which one might suppose to be coupled with it, is encountered only on the basis of the temporality which concerns itself with time. Inasmuch as both time-reckoning and the clock are founded upon the temporality of Dasein, which is constitutive for this entity as historical, it may be shown to what extent, ontologically, the use of clocks is itself historical, and to what extent every clock as such ‘has a history’. BTMR §80
The time which is made public by our measuring it, does not by any means turn into space because we date it in terms of spatial measurementrelations. Still less is what is existential-ontologically essential in the measuring of time to be sought in the fact that dated ‘time’ is determined numerically in terms of spatial stretches and in changes in the location of some spatial Thing. What is ontologically decisive lies rather in the specific kind of making-present which makes measurement possible. DATING [SZ:418] in terms of what is ‘spatially’ present-at-hand is so far from a spatializing of time that this supposed spatialization signifies nothing else than that an entity which is present-at-hand for everyone in every “now” is made present in its own presence. Measuring time is essentially such that it is. necessary to say “now”; but in obtaining the measurement, we, as it were, forget what has been measured as such, so that nothing is to be found except a number and a stretch. BTMR §80