Затем можно использовать as.POSIXct()
для создания столбца даты / времени и подмножества.
d$Date.px <- as.POSIXct(paste(d$Date, d$Time))
subset <- d[d$Date.px < as.POSIXct("2019-02-12 13:32"), ]
# > subset
# Sensor Date Time CO2.ppm. Type calCO2 Date.px
# 2 N1 2019-02-12 13:30 583 Naveed 400 2019-02-12 13:30:00
# 3 N1 2019-02-12 13:30 583 Naveed 400 2019-02-12 13:30:00
# 4 N1 2019-02-12 13:30 583 Naveed 400 2019-02-12 13:30:00
# 5 N1 2019-02-12 13:31 583 Naveed 400 2019-02-12 13:31:00
Данные
d <- structure(list(Sensor = structure(c(2L, 2L, 2L, 2L, 2L, 2L), .Label = c("<fctr>",
"N1"), class = "factor"), Date = structure(c(2L, 2L, 2L, 2L,
2L, 2L), .Label = c("<date>", "2019-02-12"), class = "factor"),
Time = structure(c(2L, 2L, 2L, 3L, 4L, 5L), .Label = c("<time>",
"13:30", "13:31", "13:32", "13:33"), class = "factor"), CO2.ppm. = structure(c(2L,
2L, 2L, 2L, 2L, 2L), .Label = c("<dbl>", "583"), class = "factor"),
Type = structure(c(2L, 2L, 2L, 2L, 2L, 2L), .Label = c("<chr>",
"Naveed"), class = "factor"), calCO2 = structure(c(2L, 2L,
2L, 2L, 2L, 2L), .Label = c("<dbl>", "400"), class = "factor"),
Date.px = structure(c(1549974600, 1549974600, 1549974600,
1549974660, 1549974720, 1549974780), class = c("POSIXct",
"POSIXt"), tzone = "")), row.names = 2:7, class = "data.frame")