New macros for showing date and time of history data are useful for notification message, especially using Zabbix proxy.

Example,

{ITEM.DATE}

or

{HISTORY.DATE}

: show the date of history data which generate the event

{ITEM.TIME}

or

{HISTORY.TIME}

: show the time of history data which generate the event

Zabbix server already has

{EVENT.DATE}

macro to display "the time of event generated".
However, If Zabbix proxy keeps data on offline buffer because of network problem, event time is delayed.
In this case user cannot understand when the problem was happened correctly from the notification message.