Force to show all labels in axis
atT <- structure(c(1672520400, 1675198800, 1677618000, 1680296400, 1682888400, 1685566800, 1688158800, 1690837200, 1693515600, 1696107600, 1698786000, 1701378000, 1704056400, 1706734800, 1709240400, 1711918800, 1714510800, 1717189200, 1719781200, 1722459600, 1725138000, 1727730000, 1730408400, 1733000400, 1735678800), class = c("POSIXct", "POSIXt"), tzone = "Asia/Riyadh") # Work as expected plot(x = atT, y=rep(1, length(atT)), xaxt="n") axis(side = 1, at=atT, labels = as.character(seq_along(atT))) # Only first label is shown plot(x = atT, y=rep(1, length(atT)), xaxt="n") axis(1, at=atT, label=c("Jan-2023", "", "", "", "", "", "Jul-2023", "", "", "", "", "", ...