How to create random gaps in a time series with different lengths?

For my Masterthesis i have to check different gap-filling methods on an existing dataset. Therefore i have to add artificial gaps of different lengths (1h, 5h..) so i can gap fill them with different methods. Is there an easy function to do so?

here is an example of the dataframe:

   structure(list(DateTime = structure(c(1420074000, 1420077600, 
1420081200, 1420084800, 1420088400, 1420092000, 1420095600, 1420099200, 
1420102800, 1420106400), class = c("POSIXct", "POSIXt"), tzone = "UTC"), 
    `Dd 1-1` = c(0.0186269166666667, 0.0242605625, 0.00373020138888889, 
    0.000966965277777778, 0.0119253611111111, 0.0495888958333333, 
    0.02014125, 0.0306862638888889, 0.0324395694444444, 0.0191942152777778
    ), `Dd 1-3` = c(0.0242500833333333, 0.0349086388888889, 0, 
    0.00135595138888889, 0.0221090138888889, 0.0600941527777778, 
    0.0462282986111111, 0.0171887638888889, 0.0481975347222222, 
    0.0226582152777778), `Dd 1-5` = c(0.0212732152777778, 0.0284445347222222, 
    0.00276098611111111, 0.0142581875, 0.0276248958333333, 0.0328644027777778, 
    0.0495009166666667, 0.0173377777777778, 0.0384788194444444, 
    0.017663875), luecken = c(0.0186269166666667, 0.0242605625, 
    0.00373020138888889, 0.000966965277777778, 0.0119253611111111, 
    0.0495888958333333, 0.02014125, 0.0306862638888889, 0.0324395694444444, 
    0.0191942152777778)), row.names = c(NA, 10L), class = c("tbl_df", 
"tbl", "data.frame"))