did not determine at all in what sense the public time expressed "is," or whether it can be addressed as existing [seiend] at all. Before any decision as to whether public time is "merely subjective" or whether it is "objectively real," or neither of the two, the phenomenal character of public time must first be determined more precisely.
Making time public does not occur occasionally and subsequently. Rather, since as ecstatic and temporal Dasein is always already disclosed, and because understanding and interpretation belong to existence, time has also already made itself public in taking care. One orients oneself according to it, so that it must somehow be available for everyone.
Although taking care of time can be carried out in the mode of dating that we characterized as based on events in the surrounding world, this always occurs in the horizon of a taking care of time that we know as astronomical and calendrical time-reckoning. This reckoning is not a matter of chance, but has its existential and ontological necessity in the fundamental constitution of Dasein as care. Since Dasein essentially exists as thrown and entangled, it interprets its time heedfully by way of a reckoning with time. In this reckoning, the "real" making [412] public of time temporalizes itself so that we must say that the thrownness of Dasein is the reason "there is" public time. If we are to demonstrate that public time has its origin in factical temporality, and if we are to assure ourselves that this demonstration is as intelligible as possible, we must characterize beforehand the time interpreted in general in the temporality of taking care, if only to make clear that the essence of taking care of time does not lie in the application of numerical procedures in dating. What is existentially and ontologically decisive about reckoning with time must not be seen in the quantification of time, but must be more primordially conceived in terms of the temporality of Dasein reckoning with time.
"Public time" turns out to be the time "in which" innerworldly things at hand and objectively present are encountered. This requires that we call these beings unlike Dasein beings within-time. The interpretation of within-timeness gives us a more primordial insight into the essence of "public time" and at the same time makes it possible to define its "being."
The being of Dasein is care. This being exists entangled as thrown. Delivered over to the "world" discovered with its factical there and dependent upon it in taking care, Dasein awaits its potentiality-of-being-in-the-world in such a way that it reckons with and on whatever is in eminent relevance for the sake of its potentiality-of-being. Everyday circumspect being-in-the-world needs the possibility of sight, that is, brightness, if it is to take care of things at hand within what is present. With the factical disclosedness of world, nature has been discovered for Dasein. In its thrownness Dasein is subject to the changes of day