Aggregate data by week or few days - r

Question

I'm trying to aggregate a data frame as to obtain a table with weekly averages of a variable. I found the following package provides a nice solution, and I've been using it for aggregating data yearly and monthly. However, the function to aggregate data weekly simply is not working as described. Does anyone has an idea how I can fix this up?
For instance, following the manual:
require(TSAgg)
#Load the data:
data(foo)
##Format the data using the timeSeries function.
foo.ts<-timeSeries(foo[,1], "%d/%m/%Y %H:%M",foo[,3])
##Aggregate the data into 6 days blocks using max
(mean.month <- monthsAgg(foo.ts,mean,6))
#Aggregate the data into weeks, using 7 days and mean:
(foo.week<-daysAgg(foo.ts,mean,7) )
The last command doesn't work. The function is the following:
daysAgg <-
function (data, process, multiple = NULL, na.rm = FALSE)
{
if (is.null(multiple)) {
multiple = 1
}
if (multiple == 1) {
day <- aggregate(data[, 8:length(data)], list(day = data$day,
month = data$month, year = data$year), process, na.rm = na.rm)
days <- ymd(paste(day$year, day$month, day$day))
data2 <- data.frame(date = days, data = day[, 4:length(day)])
names(data2) <- c("Date", names(data[8:length(data)]))
return(data2)
}
temp <- data
day <- aggregate(list(data[, 8:length(data)], count = 1),
list(day = data$day, month = data$month, year = data$year),
process, na.rm = na.rm)
days <- ymd(paste(day$year, day$month, day$day))
data <- data.frame(date = days, day[, 5:length(day) - 1],
count = day[length(day)])
days = paste(multiple, "days")
all.dates <- seq.Date(as.Date(data$date[1]), as.Date(data$date[length(data[,
1])]), by = "day")
dates <- data.frame(date = all.dates)
aggreGated <- merge(dates, data, by = "date", all.x = TRUE)
aggreGated$date <- rep(seq.Date(as.Date(data$date[1]), as.Date(data$date[length(data[,
1])]), by = days), each = multiple, length = length(all.dates))
results <- aggregate(list(aggreGated[2:length(aggreGated)]),
list(date = aggreGated$date), process, na.rm = TRUE)
results <- subset(results, results$count != 0)
results <- results[, -length(results)]
names(results) <- c("Date", names(temp[8:length(temp)]))
return(results)
}

Answer 1

The problem in the code stems from its usage of the function ymd, which attaches " UTC" to the end of all dates it outputs. It is possible to overload the function by defining ymd again using
ymd <- function(x) {
as.Date(x, "%Y %m %d")
}
before you call daysAgg.