1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
implementation module DateExtensions
import _SystemArray
from StdFunc import flip
from Data.Func import $
import System.Time
import iTasks
import iTasks.Extensions.DateTime
derive class iTask Day
instance toString Day
where
toString Sunday = "Sunday"
toString Monday = "Monday"
toString Tuesday = "Tuesday"
toString Wednesday = "Wednesday"
toString Thursday = "Thursday"
toString Friday = "Friday"
toString Saturday = "Saturday"
(+~) infixl 6 :: Timestamp Int -> Timestamp
(+~) (Timestamp t) i = Timestamp (t+i)
(-~) infixl 6 :: Timestamp Int -> Timestamp
(-~) (Timestamp t) i = Timestamp (t-i)
timestampToGmDate :: (Timestamp -> Date)
timestampToGmDate = toDate o timestampToGmDateTime
nextHour :: DateTime -> DateTime
nextHour t = timestampToGmDateTime (Timestamp ts`)
where
(Timestamp ts) = utcDateTimeToTimestamp t
ts` = ts + 3600 - (ts rem 3600)
nextDay :: (Date -> Date)
nextDay = timestampToGmDate o (flip (+~) 86400) o utcDateToTimestamp
// https://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week#Schwerdtfeger.27s_method
dayOfWeek :: Date -> Day
dayOfWeek date = days.[(d + e + f + g + g / 4) rem 7]
where
days :: {Day}
days = {Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday}
d = date.Date.day
e = {#0,3,2,5,0,3,5,1,4,6,2,4}.[date.Date.mon-1]
f = {#0,5,3,1}.[c rem 4]
(c,g) = if (date.Date.mon >= 3)
(y / 100, y - 100 * c)
((y-1) / 100, y - 100 * c - 1)
y = date.Date.year
previous :: Day Date -> Date
previous day date
| dayOfWeek date === day = date
| otherwise = previous day $ timestampToGmDate $ minus 86400 $ utcDateToTimestamp date
where
minus :: Int Timestamp -> Timestamp
minus i (Timestamp t) = Timestamp (t-i)
|
