Good morning all...

Hope this helps a little Paul...

http://aviationglossary.com/night/


UK Air Navigation Order – Night means the time between half an hour after sunset and half an hour before sunrise (both times inclusive), sunset and sunrise being determined at surface level.

Transport Canada  provides some guidance on the history and the changes they implemented in 2003 of  their definition of Night & Day:

The definitions “day” and “night” in subsection 101.01(1) of the Canadian Aviation Regulations  are replaced by the following:

“day” or “daylight” means the time between the beginning of morning civil twilight and the end of evening civil twilight;(jour)

“night” means the time between the end of evening civil twilight and the beginning of morning civil twilight; (nuit)

Description

The Regulations Amending the Canadian Aviation Regulations (Part I) revise the existing definitions of “day” and “night” in section 101.01 Interpretation of Part I General Provisions of the Canadian Aviation Regulations (CARs). Many regulations and standards apply specifically to aviation operations at night or differentiate between operations permitted by day and those permitted at night. Often air operators or pilots holding Canadian aviation documents are restricted to day only operations. Thus, the existence in the CARs of definitions of “day” and of “night” is an important regulatory tool as well as having significant economic implications for the aviation industry.

Prior to these amendments, both definitions relied on a period of one-half hour before sunrise (day) and one-half hour after sunset (night). The intent of the definitions was to include the lighting and visibility conditions of twilight with those of day for aviation operational purposes. They took into account the latitudes and seasons during which the sun neither rises nor sets daily by defining day and night in these places in relation to the centre of the sun’s disc with respect to the horizon. Many of the northern regions of Canada lie in latitudes where, in the spring and fall, the sun rises and sets daily but does so after a lengthy period of twilight. This period, in these locations, can be up to two hours, i.e., much longer than the half-hour allowed for in the aviation-specific definitions of “day” and “night” prior to these amendments. At times and places where the sun does rise and set daily but with a period of twilight at certain seasons which is longer than the half-hour, the previous definition of “night” was unnecessarily restrictive. In these latitudes, at these times, “night” began, with its additional operational restrictions, one half-hour after sunset although the light conditions might have been sufficient for day operations for much longer.

To avoid ambiguity, in English, between the use of “day” to mean daylight conditions and “day” to mean a period of twenty-four hours, the English definition of “day”, when the context refers to daylight conditions, is revised to refer to “day or daylight”. This ambiguity does not exist in French. Therefore, the French definition refers only to “day”. “day or daylight” is defined as “the time between the beginning of morning civil twilight and the end of evening civil twilight”. Since the use of “night” involves no such ambiguity, “night” is defined as “the time between the end of evening civil twilight and the beginning of morning civil twilight”. These changes acknowledge geographical variations in light conditions at different times of year and reduce the daily period during which restrictions related to night operating conditions apply in northern districts.

Some Additional Information:

3.0 NIGHT VISUAL FLIGHT

Accidents occurring in other than daylight conditions comprised a disproportionately large number of VFR-into-IMC accidents. Approximately 10% of all Canadian accidents occur during the hours of darkness, which parallels estimates of the general level of night flying activity (also 10%). However, VFR-into-IMC accidents occurring during the hours of darkness accounted for almost 30% of the total study accidents. Analysis pointed to three issues: night VFR weather minima; the conditions for obtaining and maintaining a night endorsement; and weather briefings

You are most welcome Paul...

Several of the things I did not post or mention as I just thought of them now (old grey matter is not like it used to be... ) is:

Civilian Float Aircraft and Seaplanes must operate during daylight hours...
Now there are several regulations which allow them to land at a Lighted Seaplane Base/Aerodrome which has some form of a lighted water runway.  These are now few and far between. Can be found in the Water Aerodrome Supplement which is published once a year by the Government of Canada and has to be paid for...it is not free.

However:

If the Float Aircraft or Seaplane are Amphibians then they can operate as any other aircraft would.

A Night Endorsed Aviator with a Private Pilots Licence must perform a certain number of takeoff and landings over a period of time to keep current.

The cost of keeping current all the Flight Endorsements to the Aviators Licence today Paul is expensive.

General Aviation and Aircraft Ownership is on the increase again here in Canada which has the second largest number of licenced aviators in the world.

Link you might find interesting Paul...

http://en.wikipedia.org/wiki/Pilot_licensing_in_the_United_Kingdom

The Night Qualification may be included in a JAR-FCL pilot licence. The qualification is, subject to the relevant conditions made under JAR-FCL being satisfied, included in the holder's licence without a Skill Test being required. Additionally, subject to conditions laid down in UK legislation (which presently includes JAR-FCL, Amendment 5) governing requirements for the holder's recent flying experience, there is no requirement made which requires retesting of the holder of a Night Qualification.

The Night Qualification privileges are to, subject to regulations enforced in and by jurisdictions other than the United Kingdom, operate in Visual Meteorological Conditions at night. (UK Air Navigation Order 2009, Schedule 7 refers.) 'Night' for the purpose of this section is defined under the UK Air Navigation Order 2009 Art. 255(1) as:
"'Night' means the time from half an hour after sunset until half an hour before sunrise (both times inclusive), sunset and sunrise being determined at surface level"
The Night Rating is distinct from the Night Qualification in as much as the former is a rating included in a UK national licence and the latter in a JAR-FCL licence.

Flight Instructor and Examiner ratings extend the holder's privileges to act, respectively, as an instructor and to act as an examiner for proficiency checks and, or, skill tests. These ratings both exist in a variety of forms whose domains, or ranges of privileges, are for specified aircraft operations.