Highcharts will automatically try to find the best format for the current zoom-range. This is done if the xAxis has the TYPE 'datetime'. Next the unit of the current zoom is calculated, it could be one of:

• second
• minute
• hour
• DAY
• week
• month
• YEAR

This unit is then used find a format for the axis labels. The default patterns are:

second: '%H:%M:%S',
minute: '%H:%M',
hour: '%H:%M',
day: '%e. %b',
week: '%e. %b',
month: '%b '%y',
year: '%Y'

If you want the day to be part of the "hour"-level labels you should change the dateTimeLabelFormatsoption for that level include %d or %e. These are the available patters:

• %a: Short weekday, like 'Mon'.
• %A: Long weekday, like 'Monday'.
• %d: TWO digit day of the month, 01 to 31.
• %e: Day of the month, 1 through 31.
• %b: Short month, like 'Jan'.
• %B: Long month, like 'January'.
• %m: Two digit month number, 01 through 12.
• %y: Two digits year, like 09 for 2009.
• %Y: Four digits year, like 2009.
• %H: Two digits hours in 24h format, 00 through 23.
• %I: Two digits hours in 12h format, 00 through 11.
• %l (Lower case L): Hours in 12h format, 1 through 11.
• %M: Two digits minutes, 00 through 59.
• %p: Upper case AM or PM.
• %P: Lower case AM or PM.
• %S: Two digits seconds, 00 through 59

Highcharts will automatically try to find the best format for the current zoom-range. This is done if the xAxis has the type 'datetime'. Next the unit of the current zoom is calculated, it could be one of:

This unit is then used find a format for the axis labels. The default patterns are:

second: '%H:%M:%S',
minute: '%H:%M',
hour: '%H:%M',
day: '%e. %b',
week: '%e. %b',
month: '%b '%y',
year: '%Y'

If you want the day to be part of the "hour"-level labels you should change the dateTimeLabelFormatsoption for that level include %d or %e. These are the available patters: