copying extracted date into row, as long as date does not change - R 3.1.1 / Windows

I am trying for some time to get my head around a copy problem. I am trying to extract the date from a data frame and copy it in a new row as long as the date does not change.

I found a few discussions on different problems, but I was not getting the right results in ifelse and for loops.

The data is from the following site : http://ift.tt/17L9tn0)

data is cleaned up by removing not footer information and added column date, VECCsample2 is a sample from the link above that I used

data <- read.table('./VECCsample2.txt', sep = "", na.strings = "99999", fill=TRUE, header=FALSE, stringsAsFactors=FALSE)

# removing unneeded rows
data <- data[data$V1 != "Station", ]
data <- data[data$V1 != "-----------------------------------------------------------------------------", ]
data <- data[data$V1 != "Showalter",]
data <- data[data$V1 != "Lifted",]
data <- data[data$V1 != "LIFT",]
data <- data[data$V1 != "SWEAT",]
data <- data[data$V1 != "K",]
data <- data[data$V1 != "Cross",]
data <- data[data$V1 != "Vertical",]
data <- data[data$V1 != "Observation",]
data <- data[data$V1 != "Totals",]
data <- data[data$V1 != "Convective",]
data <- data[data$V1 != "CAPE",]
data <- data[data$V1 != "CINS",]
data <- data[data$V1 != "Equilibrum",]
data <- data[data$V1 != "Level",]
data <- data[data$V1 != "LFCT",]
data <- data[data$V1 != "Bulk",]
data <- data[data$V6 != "Condensation",]
data <- data[data$V1 != "Mean",]
data <- data[data$V6 != "thickness:",]
data <- data[data$V1 != "Precipitable",]
data <- data[data$V1 != "hPa",]
data <- data[data$V1 != "PRES",]

# renaming headers
names(data) <- c("PRES", "HGHT", "TEMP", "DEWP", "RELH", "MIXR", "DRCT", "SKNT", "THTA", "THTE", "THTV") 
# adding empty date column 
data$date <- 0

an example of the data

row.names   PRES    HGHT    TEMP    DEWP    RELH    MIXR    DRCT    SKNT    THTA    THTE    THTV    date
1   1   42809.0 VECC    Calcutta    Observations    at  00Z 01  January 2014            0
2   5   1004.0  6   28.2    26.0    88  21.64   180 3   301.0   365.1   304.9   0
3   6   1000.0  42  27.2    24.2    84  19.45   180 4   300.4   357.7   303.8   0
4   7   978.0   239 25.4    22.5    84  17.85   180 11  300.4   353.0   303.6   0
5   8   960.0   403 23.8    21.0    84  16.61   215 17  300.4   349.3   303.4   0
6   9   950.0   496 30.4    18.4    49  14.22   235 21  308.0   351.4   310.7   0
7   120 42809.0 VECC    Calcutta    Observations    at  00Z 02  January 2014            0
8   124 1005.0  6   26.2    23.3    84  18.30   45  2   298.9   352.5   302.2   0
9   125 1000.0  50  25.0    20.5    76  15.43   60  6   298.1   343.2   300.9   0
10  126 974.0   282 23.4    20.6    84  15.95   108 14  298.8   345.4   301.6   0
11  127 965.0   364 23.5    20.8    85  16.35   125 17  299.7   347.7   302.6   0

I am trying to extract the date (01 January 2014) and copy it in the date column. The 1 January 2014 needs to be copied until the separator "VECC" is read. The output should look like

row.names   PRES    HGHT    TEMP    DEWP    RELH    MIXR    DRCT    SKNT    THTA    THTE    THTV    date
1   1   42809.0 VECC    Calcutta    Observations    at  00Z 01  January 2014            0
2   5   1004.0  6   28.2    26.0    88  21.64   180 3   301.0   365.1   304.9   01 January 2014
3   6   1000.0  42  27.2    24.2    84  19.45   180 4   300.4   357.7   303.8   01 January 2014
4   7   978.0   239 25.4    22.5    84  17.85   180 11  300.4   353.0   303.6   01 January 2014
5   8   960.0   403 23.8    21.0    84  16.61   215 17  300.4   349.3   303.4   01 January 2014
6   9   950.0   496 30.4    18.4    49  14.22   235 21  308.0   351.4   310.7   01 January 2014
7   120 42809.0 VECC    Calcutta    Observations    at  00Z 02  January 2014            0
8   124 1005.0  6   26.2    23.3    84  18.30   45  2   298.9   352.5   302.2   02 January 2014
9   125 1000.0  50  25.0    20.5    76  15.43   60  6   298.1   343.2   300.9   02 January 2014
10  126 974.0   282 23.4    20.6    84  15.95   108 14  298.8   345.4   301.6   02 January 2014
11  127 965.0   364 23.5    20.8    85  16.35   125 17  299.7   347.7   302.6   02 January 2014

I have tried different options with if, ifelse, for loops, which did not did what I would like The one that provided the best option is :

pattern = "VECC"
name_row <- grep(pattern, data$HGHT)
name_row_date <- data[name_row,]
if (grep(pattern, data$HGHT)) data$date <- name_row_date$DRCT

or

for (index in 1:nrow(data)) { 
    row = data[index, ] 

    if (row[index,3] == "VECC") {
        date <- row[row$SKNT,]
        data$date <- "NA"
    }
    if (row[index,3] != "VECC")
        data$date <- date
}

Did somebody have a similar exercise or a hint on how to solve this problem?

Thank you in advance.