Time Range Selector

Absolute, relative, and predefined time ranges, and the DateMath notation behind them.

The Time Range Selector appears wherever akenza shows data over a period, from a dashboard to a device's message history. It supports three ways of setting the range:

Way	What it is	Use it when
Date range	An absolute start and end.	You are looking at a fixed period, such as a particular week of an incident.
Relative selection	An expression in DateMath notation, evaluated whenever the view is opened.	The range should follow the present, such as "the last 24 hours".
Quick selection	A predefined relative range chosen from a list.	One of the common ranges already fits, which is most of the time.

A relative range matters most on anything left open or shared. A dashboard on a signage screen, or one reached through a public link, keeps showing the right window because the expression is evaluated each time rather than baked in.

Rounding happens in the workspace time zone, not the viewer's, so now/d is the start of the day as the workspace defines it. See General Settings for where that is set.

DateMath notation

An expression is formed from three parts:

1. An anchor date, either now or a date string ending with ||.

2. An operator: + to add to the anchor, - to subtract from it, or / to round it.

3. A time unit.

Unit	Meaning
y	Year
Q	Quarter
M	Month
w	Week
d	Day
h	Hour
m	Minute
s	Second
ms	Millisecond

M is month and m is minute. The notation is case sensitive, so now-1M is a month ago and now-1m is a minute ago.

Rounding

/ rounds the date to the boundary of the given unit. At the start of a range it rounds down, to the beginning of that unit; at the end of a range it rounds up, to the end of it.

That is what distinguishes a whole period from a period in progress:

• now/d - now/d covers the whole of today, midnight to midnight.

• now/d - now covers today so far, midnight until this moment.

Examples

Taking now as 2025-01-01 12:00:00:

Expression	Reads as	Result
now+1d	now plus one day	2025-01-02 12:00:00
now-1m	now minus one minute	2025-01-01 11:59:00
now-1s/h	now minus one second, rounded to hours	2025-01-01 11:00:00
2025.01.01||+1M/d	2025.01.01 plus one month, rounded to days	2025-02-01 00:00:00

The third example is worth reading twice: subtracting one second crosses back into the previous hour, and the rounding then takes it to the start of that hour rather than the one now is in.

Predefined relative time ranges

The quick selection offers these ranges. The expressions are shown so that you can start from one and adapt it in a relative selection.

Hour

Range	Expression
This hour	now/h - now/h
This hour so far	now/h - now
Last hour	now-1h/h - now-1h/h
Last 1h	now-1h - now
Last 12h	now-12h - now
Last 24h	now-24h - now
Last 48h	now-48h - now

Day

Range	Expression
Today	now/d - now/d
Today so far	now/d - now
Yesterday	now-1d/d - now-1d/d
This day last week	now-7d/d - now-7d/d
Last 7 days	now-7d - now
Last 30 days	now-30d - now
Last 90 days	now-90d - now

Week

Range	Expression
This week	now/w - now/w
This week so far	now/w - now
Previous week	now-1w/w - now-1w/w

Month

Range	Expression
This month	now/M - now/M
This month so far	now/M - now
Previous month	now-1M/M - now-1M/M
Last 6 months	now-6M - now

Quarter

Range	Expression
This quarter	now/Q - now/Q
This quarter so far	now/Q - now
Previous quarter	now-1Q/Q - now-1Q/Q

Year

Range	Expression
This year	now/y - now/y
This year so far	now/y - now
Previous year	now-1y/y - now-1y/y
Last 1 year	now-1y - now

Note the difference between the two families. Last 24h is a rolling window ending now, while Yesterday is a fixed calendar day. Comparing one period against another is only meaningful with the rounded forms, since a rolling window starts at a different point every time it is evaluated.