strptimeNoSummer: strptimeNoSummer

In twMisc: Utility functions of tw

Description

deprecated: Parse time given as character with ignoring daylight savings.

Usage

strptimeNoSummer(x, format, hourOffset = -1, tz = "CET", 
    ...)

Arguments

x	character vector holing the times
format	format argument to strptime such as format="%d.%m.%y %H:%M"
hourOffset	offset of measurement time zone from UTC in hours
tz	time zone attribute for printing
...	futher arguments to strptime such as format="%d.%m.%y %H:%M"

Details

Further time Functionality of package twMisc

• parsing a character that is all winter time: this method

• convert to all winter time (UTC): convertToWinterUTC

The String is parsed using time zone UTC, where not daylight shifts occur. Next the hour offset is added, and the tzone attribute is changed.

Better uses a corresponding time zone withotu DTS (e.g. 'Etc/GMT-1' instead of CET) (see example)

Value

POSIXct vector, printing in summer time during summer.

Author(s)

Thomas Wutzler

See Also

twMisc

Examples

# time series all recored in CET withoug switching to summer time between 2 and 3
tmpd<- c("2010-03-28 00:00:00"
    ,"2010-03-28 01:00:00"
    ,"2010-03-28 02:00:00"
    ,"2010-03-28 03:00:00"
    ,"2010-03-28 04:00:00"
)

# recommended solution: parse in UTC or 'Etc/GMT-1'
(tmp.GMT1 <- as.POSIXct(strptime(tmpd,'%Y-%m-%d %H:%M:%S',tz="Etc/GMT-1")))
plot(seq_along(tmp.GMT1) ~ tmp.GMT1)


# problems with daylight savings
# R automatically switches between CET and CEST 
(tmp.cet <- as.POSIXct(strptime(tmpd,'%Y-%m-%d %H:%M:%S',tz="CET")))

# printed in summer time 
(tmp.cet2 <- strptimeNoSummer(tmpd))
# note the missing hour 2, however time differences are preserved
plot(seq_along(tmp.cet2) ~ tmp.cet2)
diff(tmp.cet2)

# or use the time offset field in POSIXlt
tmp.cetz <- as.POSIXct(strptime(paste0(tmpd," +0100"),'%Y-%m-%d %H:%M:%S  %z'), tz="CET")
#tmp.cetz <- as.POSIXct(strptime(paste0(tmpd," +0100"),'%Y-%m-%d %H:%M:%S  %z'))
plot(seq_along(tmp.cetz) ~ tmp.cetz)
all(tmp.cetz == tmp.cet2)

twMisc documentation built on May 2, 2019, 6:11 p.m.