Error message when usning window() in future_sapply() and plan(multisession),

[Code3020]

Problem description
future_sapply() and plan(multisession) returned error messages of start being before end in window() .

Example
library(zoo)
library(lubridate)
library(future)
library(future.apply)

Example 1:
df$Min10 <- future_spply(df$time, function(t) mean(window(z, start=t-10*60, end=t)))
df$P10 <- future_sapply(df$time, function(t) mean(window(z, start=t, end=t+10*60)))

Example 2
plan(multisession, workers = 4)
f <- future({

df$Min10 <- spply(df$time, function(t) mean(window(z, start=t-10*60, end=t)))
df$P10 <- sapply(df$time, function(t) mean(window(z, start=t, end=t+10*60)))

Error messages
The error messages are the same for both examples.

Error in window.default(z, start = t - 10 * 60, end = t) :
'start' cannot be after 'end'
In addition: Warning message:
In window.default(z, start = t, end = t + 10 * 60) :
'end' value not changed