Editing Template:Birth and death year and age (section)

=== <nowiki>{{Birth year and age}}</nowiki> ===
Let us assume:
#that the person in question was born some time in {{#expr: {{CURRENTYEAR}} - 55}}; and
#that the present date is {{CURRENTDAY}} {{CURRENTMONTHNAME}} {{CURRENTYEAR}}.

*If the person was born after {{#time:d F Y|now - 55 years}} then they will be {{age|{{#time:d F Y|now - 55 years + 1 day}}|{{#time:Y-m-d|now}}}} years old on {{#time:d F Y|now}} as they have not had their 55th birthday yet. On the other hand, if they were born exactly on or before {{#time:d F Y|now - 55 years}}, then they will be {{age|{{#time:d F Y|now - 55 years}}|{{#time:Y-m-d|now}}}} years old.
*:Therefore, the template {{tlx|Birth year and age|{{#expr: {{CURRENTYEAR}} - 55}} }}
*:displays their birth year and age as: {{birth year and age|{{#expr: {{CURRENTYEAR}} - 55}}}}
*Optionally, if we know the person's birth month but not the day, we can also have the template display the month.
*:Let us assume that the person was born in June {{#expr: {{CURRENTYEAR}} - 55}}. Therefore:
*:*If it is presently January {{CURRENTYEAR}}, then this year the person has not had their birthday yet. Therefore, the template {{tlx|Birth year and age|{{#expr: {{CURRENTYEAR}} - 55}}|6}} displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 54).
*:*If it is presently June {{CURRENTYEAR}}, we do not know whether the person has had their birthday this year yet since their day of birth is unknown. Therefore, the template displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 54–55).
*:*If it is presently December {{CURRENTYEAR}}, then this year the person has already had their birthday. Therefore, the template displays their birth year and age as: {{#expr: {{CURRENTYEAR}} - 55}} (age 55).