# What does “on day 50” mean?

In this sentence:

“Since the aggregates sank so rapidly and the water column was more or less ‘empty’ on day 50, they must have settled out,” Smetacek argues. “Layers of fluff have been reported from various regions, including the Southern Ocean.”

What does “on day 50” mean in that sentence? Does it mean “in 50 days”?

-

Yes, that’s right. It means fifty days out from the start of some time period, such as a journey or since the start of some experiment.

-
i see, thanks a lot! – clay686 Sep 22 '12 at 1:49
+1 But fifty full days may not have passed. If it started on noon of Day1 and you measured on Day50 at noon, 49 days worth of hours have passed, but it is still Day50. If there were a need for more precison, the phrase should be "at the conclusion of 50 days.* – bib Sep 22 '12 at 2:44
Some technical writers label the first day of the experiment "day 0". – user21497 Sep 22 '12 at 3:03
@bib: I agree. There is some numbering of days that is being referred to, and this is an event that occurred on the day designated 50 by this numbering system. More than that, we can't say. – David Schwartz Sep 23 '12 at 7:22
in normal English we understand "day 1" or "the first day" to be the day some event started, and count from there. If a time period started on April 1, than April 1 is "day 1" or "the first day", Aprili 2 is "day 2" or "the second day", etc. Other ways of counting are possible, and you could argue are better, but they're not how people normally count and require explanation if used. – Jay Apr 4 at 14:00

If English were logical, I'd say that "on day fifty" means "forty-nine days out." Day one is the first day, day two is one day out, day three is two days out, etc.

Since English is not logical, I'll just say that "on day fifty" is ambiguous.

-
English is more logical compared with Chinese, I think. As to this question, the first day shall be also counted. – clay686 Sep 22 '12 at 2:23
@clay686 Can you provide some documentation that (a) English is a logical language, and that (b) it's more logical than Chinese? I find both assertions impossible to accept, but I'm open to being persuaded by concrete evidence of the accuracy of these claims. I think Japanese is the most "logical" of the languages that I've studied, much more so than English, but I could easily be wrong about that. I suppose it depends on which connotation of logical one means. The best English essays are definitely more "logical" than the best Chinese essays, but that's culture, not linguistics. – user21497 Sep 22 '12 at 3:13
@clay686: "Watch what you say, or they'll be calling you a radical" (Supertramp, The Logical Song) – J.R. Sep 22 '12 at 8:17