Calendar Tools

Purpose

Although part of the Search pages, Calendar Tools does not really represent a search feature as such -- no user-driven query against the Hirtius database will be issued by this page, for instance. By offering a direct access to the underlying functions that have been used to implement Calendar View however, we hope that the set of tools presented here will prove a useful support for your historical research.

To try and be as open as possible, each tool will show all intermediate steps it used in reaching the displayed result (when applicable).

Here is the list of the currently available calendar-related tools:

computing the number of days elapsed between any two random dates, where each date can be specified in any of the Supported Eras
computing the date resulting from adding or subtracting a user-specified number of days to/from a date. Both the starting date and the result can be expressed in any of the Supported Eras (not necessarily the same)
converting any given date between any of the Supported Eras (where compatible)
computing the Julian Day Number for any given date and a specified era
converting any given Julian Day Number into the equivalent date in the specified era

In all of these cases, checks will be carried out to make sure the combination of date, era and/or Julian Day Number are compatible (i.e. that they fall within the expected range).

A Caveats section at the bottom of the page will remind you what the ranges are for all supported calendaring systems and whether their proleptic use is supported or not by the application.

Getting There...

To reach the Calendar Tools Page:

From the Main Application Menu (or indeed almost any other Project Hirtius page), click on the "Search" icon in the header (). This gets you to the Basic and Timeline Search Page in "basic" or "full text search" mode.
Click on the Calendar Tools link in the navigation bar just below the page header. This gets you to the Calendar Tools in "tool selection" mode.
Use the Calendar Tool drop-down to make your selection and click Next to reach the tool-specific data entry form.

Modes

The Calendar Tools page supports 6 different modes of operation:

Calendar Tool selection
Interval between two dates
Add/Subtract days to/from date
Conversion between eras
Convert date to JDN
Convert JDN to date

Controls

Calendar Tool selection

Navigation bar

At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links. On sub-pages (such as the "Object Type Selection" or the "Search Result" page), the "current" tab will be rendered in regular font and link back to the previous step (the query terms entry form, for instance).

Calendar Tool drop-down

Select the desired tool in the list:

Interval between two dates
Add/Subtract days to/from date
Conversion between eras
Convert date to JDN
Convert JDN to date

Next button

Submits your choice and reaches the next screen (the appropriate data entry form).

Interval between two dates

Navigation bar: At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links.
From field: Start date for the interval computation. The expected format is the so-called "historical" one -- a variation on the ISO one with slash as separator and an optional initial minus sign ((-)YYYY/MM/DD).
From Era drop-down: Specifies the Era in which the Start date (From field) is expressed.
To field: End date for the interval computation. The expected format is the so-called "historical" one -- a variation on the ISO one with slash as separator and an optional initial minus sign ((-)YYYY/MM/DD).
To Era drop-down: Specifies the Era in which the End date (To field) is expressed.
Compute button: Submits the HTML form fields contents to be used as parameters for the computation and returns to the Calendar Tools page to display the result and accept data entry for a new computation.

Add/Subtract days to/from date

Navigation bar: At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links.
Base Date field: Date to be used as base for the addition or subtraction opertation. The expected format is the so-called "historical" one -- a variation on the ISO one with slash as separator and an optional initial minus sign ((-)YYYY/MM/DD).
Base Date Era drop-down: Specifies the Era in which the Base Date field is expressed.
Operation drop-down: Specifies the operation to be performed ('+' for addition, '-' for subtraction).
Days field: The number of days to add or subtract. A positive integer value is expected.
Result As Era drop-down: Specifies the Era in which the Base Date field is expressed.
Compute button: Submits the HTML form fields contents to be used as parameters for the computation and returns to the Calendar Tools page to display the result and accept data entry for a new computation.

Conversion between eras

Navigation bar: At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links.
Date field: Start date for the conversion. The expected format is the so-called "historical" one -- a variation on the ISO one with slash as separator and an optional initial minus sign ((-)YYYY/MM/DD).
Era drop-down: Specifies the Era in which the Date field is expressed.
Convert button: Submits the HTML form fields contents to be used as parameters for the computation and returns to the Calendar Tools page to display the result and accept data entry for a new computation.

Please note: As there are currently only two era choices available, there is no need to specify the target one. It will, by definition, be the one not selected as source.

Convert date to JDN

Navigation bar: At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links.
Date field: Start date for the conversion. The expected format is the so-called "historical" one -- a variation on the ISO one with slash as separator and an optional initial minus sign ((-)YYYY/MM/DD).
Era drop-down: Specifies the Era in which the Date field is expressed.
Convert button: Submits the HTML form fields contents to be used as parameters for the computation and returns to the Calendar Tools page to display the result and accept data entry for a new computation.

Convert JDN to date

Navigation bar: At the top of the page, just below the header, you'll find links that you can use to switch between the four main search modes: Basic, Timeline, Advanced and Calendar Tools. This control acts like a set of "Tabs", where the currently active one is rendered as plain text, and other available choices are rendered as bold-face font links.
JDN field: The Julian Day Number to convert. An integer value is expected. The canonical definition of the Julian Day would mandate a null or positive value, but the function will also produce valid results for (reasonable) negative values.
As Era drop-down: Specifies the Era in which the resulting date should be expressed.
Convert button: Submits the HTML form fields contents to be used as parameters for the computation and returns to the Calendar Tools page to display the result and accept data entry for a new computation.