Rescheduled time unit

Its weird to see the time unit as below.

> repeat {
+     startTime <- now('Asia/Tokyo')
+     cat('Now is', as.character(now('Asia/Tokyo')), '(Asia/Tokyo).\n')
+     sleepTime <- startTime + 5*60 - now('Asia/Tokyo')
+     if (sleepTime > 0)
+         Sys.sleep(sleepTime)
+ }
Now is 2018-06-20 15:02:48 (Asia/Tokyo).
Now is 2018-06-20 15:02:53 (Asia/Tokyo).
Now is 2018-06-20 15:02:58 (Asia/Tokyo).
Now is 2018-06-20 15:03:03 (Asia/Tokyo).

> repeat {
+     startTime <- now('Asia/Tokyo')
+     cat('Now is', as.character(now('Asia/Tokyo')), '(Asia/Tokyo).\n')
+     sleepTime <- startTime + 120*60 - now('Asia/Tokyo')
+     if (sleepTime > 0)
+         Sys.sleep(sleepTime)
+ }
Now is 2018-06-20 15:03:21 (Asia/Tokyo).
Now is 2018-06-20 15:03:23 (Asia/Tokyo).
Now is 2018-06-20 15:03:25 (Asia/Tokyo).
Now is 2018-06-20 15:03:27 (Asia/Tokyo).
Now is 2018-06-20 15:03:29 (Asia/Tokyo).
Now is 2018-06-20 15:03:31 (Asia/Tokyo).
Now is 2018-06-20 15:03:33 (Asia/Tokyo).

Working fine now...

> repeat{
+     startTime <- now('Asia/Tokyo')
+     print(as.character(now('Asia/Tokyo')))
+     print(forecastData())
+     sleepTime <- startTime + 60*60 - now('Asia/Tokyo')
+     if (sleepTime > 0)
+         Sys.sleep(sleepTime)
+ }
[1] "2018-06-20 19:57:19"
     .id ForecastDate.GMT    Currency
1 EURUSD       2018-06-19   1.1756002
2 USDJPY       2018-06-19 110.4611047
3 GBPUSD       2018-06-19   1.3276902
4 USDCHF       2018-06-19   0.9869512
5 USDCAD       2018-06-19   1.2841243
6 AUDUSD       2018-06-19   0.7396868
[1] "2018-06-20 19:58:19"
     .id ForecastDate.GMT    Currency
1 EURUSD       2018-06-19   1.1756002
2 USDJPY       2018-06-19 110.4611047
3 GBPUSD       2018-06-19   1.3276902
4 USDCHF       2018-06-19   0.9869512
5 USDCAD       2018-06-19   1.2841243
6 AUDUSD       2018-06-19   0.7396868
[1] "2018-06-20 19:59:19"
     .id ForecastDate.GMT    Currency
1 EURUSD       2018-06-19   1.1756002
2 USDJPY       2018-06-19 110.4611047
3 GBPUSD       2018-06-19   1.3276902
4 USDCHF       2018-06-19   0.9869512
5 USDCAD       2018-06-19   1.2841243
6 AUDUSD       2018-06-19   0.7396868

Test the time unit for rescheduled task...

> startTime <- now('Asia/Tokyo')
> startTime + 24*60*60 - now('Asia/Tokyo')
Time difference of 24 hours