SE hanya akan dibaca / dibaca hari ini 2017-05-04 pukul 00:00 UTC hingga 00:20 UTC.

Tantangan Anda adalah untuk menghasilkan nilai kebenaran jika SE turun / hanya membaca dan nilai palsu jika SE tidak. Anda mungkin tidak memiliki input apa pun, dan Anda harus menggunakan date builtin untuk menentukan apakah SE hanya down / read (tidak benar-benar menanyakan SE api!) Contoh output:

12:34 UTC 03 May 2017 -> false

00:00 UTC 04 May 2017 -> true

00:20 UTC 20 May 2017 -> undefined, see below

Itu perilaku yang tidak terdefinisi, karena terlalu jauh setelah waktu. Agar lebih jelas, Anda dapat mengasumsikan program Anda akan dijalankan dari UTC 8:00hari ini (5/3/17) hingga UTC 1:00besok (5/4/17).

00:21 UTC 04 May 2017 -> false

00:20 UTC 04 May 2017 -> true

00:10 UTC 04 May 2017 -> true

Perhatikan bahwa setiap nilai kebenaran atau nilai palsu diizinkan, bukan hanya truedan false. Anda harus akurat hingga detik terdekat, dan tidak mengubah jam sistem! Anda dapat berasumsi bahwa program Anda sedang dijalankan pada mesin di +0 UTCzona waktu.

05AB1E , 32 26 11 9 8 byte

žažb«21‹

Penjelasan:

ža          Is the current hour &
  žb        current minute
     «      concatenated
        ‹   less than
      21    twenty one?

Cobalah online!

JavaScript (ES6), 26 24 23 22 21 byte

Disimpan 3 byte berkat Shaggy dan 1 byte berkat Luke .

_=>new Date/12e5%72<1

Cek apakah waktu yang berlalu pada hari ini kurang dari 1200000 ms (1200 atau 20 menit). Menganggap downtime adalah 20 menit, bukan 21, yang tampaknya merupakan kasus dalam pos tertaut. 00:20UTCadalah batas atas eksklusif.

Python 2 , 41 39 byte

Disimpan 2 byte berkat Erik the Outgolfer

import time
print time.time()/1200%72<1

Cobalah online!

Menggunakan algoritma yang sama dengan jawaban JS dan Arang saya.

Jelly , 9 byte

6ŒT|0Ḍ<21

Harus TZdiatur ke UTC, yang merupakan kasus untuk TIO.

Cobalah online!

Bagaimana itu bekerja

6ŒT|0Ḍ<21  Main link. No arguments.

6ŒT        Get the current time as a string, in the format HH:MM.
   |0      Bitwise OR each character with 0. This casts the characters to int and
           maps the non-digit character : to 0.
     Ḍ     Undecimal; convert from base 10 to integer.
      <21  Compare the result with 21, so 00:00 to 00:20 return 1, all others
           return 0.

Japt, 32 11 bytes

K/12e5%72<1

Try it online!

zsh, 38 37 bytes:

date +%H\ %M|read h m;((h==0&&m<21))

bash, 40 bytes:

read h m< <(date +%H\ %M);((h==0&&m<21))

JS (ES6), 52 50 49 bytes

y=>(x=new Date).getUTCMinutes()<21&&!x.getUTCHours()

Why is Date so long? Just gets the minutes past 00:00 and returns true if they are < 21, and false otherwise.

APL (Dyalog), 14 bytes

∧/1 20>2↑3↓⎕TS

∧/ is it all-true (AND reduction) that

1 20> these numbers are greater than

2↑ the first two elements of

3↓⎕TS the current Time Stamp with three elements dropped

Charcoal, 25 bytes

‹﹪÷ＵＰtime.time⟦⟧¹²⁰⁰¦⁷²¦¹

Prints - for truthy, nothing for falsy.

Explanation

    ＵＰtime.time⟦⟧          Python function time.time()
   ÷               ¹²⁰⁰      Divided by 1200
 ﹪                    ¦⁷²   Modulo 72
‹                         ¦¹ Less than 1

Try it online!

Alice, 17 bytes

/o
\T@/4&;'-.C+n

Try it online!

Assumes to be run on a machine whose timezone is set to UTC (like the TIO server).

Explanation

While in Ordinal mode, the IP bounces diagonally up and down through the program. While in Cardinal mode, the IP wraps around the edges like most other Fungeoids.

/   Reflect to SE. Switch to Ordinal.
T   Push a string representing the current date and time, in the format:
    YYYY-MM-DDTHH:MM:SS.mmm±AA:BB
/   Reflect to E. Switch to Cardinal.
4&  Run the next command 4 times.
;   Discard four elements from the top of the stack. Since we're in Cardinal mode,
    this attempts to discard four integers. But the top stack value is a string so
    it gets implicitly converted to all the integers contained in the string. So
    year, month, day, hour, minute, seconds, milliseconds, timezone hour,
    timezone minute will be pushed separately. Then the last four of these
    will be discarded, so that we end up with the minute and the hour on
    top of the stack.
'  Push 21.
-   Subtract it from the minutes. Gives something negative for minutes 0 to 20.
.C  Compute the binomial coefficient n-choose-n. This gives 0 for negative
    results and 1 for non-negative ones. SE is down if both this value and
    the current hour are zero.
+   Add the two values. Iff they are both zero, we still get a zero.
n   Logical NOT of the value. Turns 0 into 1 and everything else into 0.
\   Reflect to NE. Switch to Ordinal.
o   Implicitly convert the result to a string and print it.
@   Terminate the program.

MATL, 10 bytes

Thanks to Dennis for several corrections

Z'1\480*7<

Try it online!

Explanation

Z'    % Push current date and time as a float. Integer part is day, decimal part is time
1\    % Modulo 1. This gives the time, in units of one day
480*  % Multiply by 480
7<    % Less than 7? Note that 21 minutes / one day equals 7 / 480. Implicitly display. 

Python 3 (NON-REPL) + time, 81 77 bytes

^{-4 bytes thanks to Bahrom}

import time;e=str(time.strftime('%H:%M'));print(e[:2]=='00'and int(e[3:])<21)

A naïve approach, turning the current date to string and analysing its characters.

Pyth, 11 bytes

&g20.d7!.d6

Online interpreter link

Bash, 55 53 51 50 bytes

-1 byte from @robbie0630's comment.

a=`date +%s`;echo $[1493856000<a&a<1493857200?1:0]

Try it online!

The advantage of this solution is that it works for any date (so will return 1 only for the period defined in the challenge, as it uses epoch time).

Swift + Foundation, 178 bytes

import Foundation;var d=String(describing:Date());func g(_ s:Int)->String{return String(d[d.index(d.startIndex,offsetBy:s)])};print(g(11)+g(12)=="00" ?Int(g(14)+g(15))!<21:false)

Quite short by swift standards. Check it out!

As in my Python answer, I basically converted the current Date to a string and have analysed its digits, depending on which I printed the bool.

R, 65 bytes

library(lubridate)
x=Sys.time()
print(all(!hour(x)&minute(x)<21))

Checks if the hour == 0 and the minute < 21.

PostgreSQL, 43 characters

select now()between'170503'and'170503 0:20'

Just because I prefer SQL for date/time calculations.

Sample run:

bash-4.3$ psql -c "select now()between'170503'and'170503 0:20'"
 ?column? 
----------
 f
(1 row)