diff --git a/config/locales/app.admin.es.yml b/config/locales/app.admin.es.yml
index 76f315b79..f3a91b3a4 100644
--- a/config/locales/app.admin.es.yml
+++ b/config/locales/app.admin.es.yml
@@ -2,17 +2,15 @@ es:
   app:
     admin:
       machines_new:
-        # add a new machine
+        #add a new machine
         declare_a_new_machine: "Declara una nueva máquina"
         watch_out_when_creating_a_new_machine_its_prices_are_initialized_at_0_for_all_subscriptions: "Cuidado al crear una nueva máquina, los precios están inicializados a 0 para todas las subscripciones."
         consider_changing_them_before_creating_any_reservation_slot: "Considera cambiarlos antes de crear cualquier ranura de reserva."
-
       machines_edit:
-        # machine edition
+        #machine edition
         machine_edit: "Editar una máquina"
-
       calendar:
-        # manage the trainings & machines slots
+        #manage the trainings & machines slots
         calendar_management: "Administración de calendario"
         trainings: "Formación"
         machines: "Máquinas"
@@ -33,7 +31,7 @@ es:
         the_machine_was_successfully_removed_from_the_slot: "La máquina se eliminó correctamente de la ranura."
         deletion_failed: "Fallo al borrar."
         DATE_slot: "{DATE} espacio:"
-        what_kind_of_slot_do_you_want_to_create: "¿Qué tipo de ranura desea crear??"
+        what_kind_of_slot_do_you_want_to_create: "¿Qué tipo de horario desea crear?"
         training: "Formación"
         machine: "Máquina"
         space: "Espacio"
@@ -42,8 +40,8 @@ es:
         select_some_machines: "Seleccione algunas máquinas"
         number_of_tickets: "Número de tickets: "
         adjust_the_opening_hours: "Ajustar el horario de apertura"
-        to_time: "to"  # context: hora. ej. 'de 18:00 a 21:00'
-        restrict_this_slot_with_labels_optional: "Restringir esta ranura con etiquetas (opcional)"
+        to_time: a
+        restrict_this_slot_with_labels_optional: "Restringir este horario con etiquetas (opcional)"
         recurrence: "Recurrence"
         enabled: "Enabled"
         period: "Period"
@@ -77,7 +75,7 @@ es:
         reservations_locked: "La reserva está bloqueada"
         unlockable_because_reservations: "No se puede bloquear la reserva en esta ranura porque existen algunas reservas no canceladas."
         delete_slot: "Delete this slot"
-        do_you_really_want_to_delete_this_slot: "Do you really want to delete this slot?"
+        do_you_really_want_to_delete_this_slot: "¿Está seguro de querer remover este horario?"
         delete_recurring_slot: "You're about to delete a recurring slot. What do you want to do?"
         delete_this_slot: "Only this slot"
         delete_this_and_next: "This slot and the following"
@@ -87,7 +85,6 @@ es:
         view_reservations: "Ver reservas"
         legend: "leyenda"
         and: "y"
-
       icalendar:
         icalendar_import: "iCalendar import"
         intro: "Fab-manager allows to automatically import calendar events, at RFC 5545 iCalendar format, from external URL. These URL are synchronized every nights and the events are shown in the public calendar."
@@ -108,9 +105,8 @@ es:
         confirmation_required: "Confirmation required"
         confirm_delete_import: "Do you really want to delete this iCalendar import?"
         delete_success: "iCalendar import successfully deleted"
-
       project_elements:
-        # management of the projects' components
+        #management of the projects' components
         name: "Name"
         projects_elements_management: "Gestión de elementos de proyectos"
         materials: "Materials"
@@ -121,9 +117,8 @@ es:
         description: "Description"
         add_a_new_licence: "Agregar una nueva licencia"
         manage_abuses: "Administrar informes"
-
       trainings:
-        # track and monitor the trainings
+        #track and monitor the trainings
         trainings_monitoring: "Trainings monitoring"
         trainings: "Trainings"
         add_a_new_training: "Add a new training"
@@ -138,7 +133,7 @@ es:
         NUMBER_reservation: "{NUMBER} {NUMBER, plural, one{reservation} other{reservations}}"
         none: "Nada"
         training_validation: "Validación de la formación"
-        training_of_the_DATE_TIME_html : "Training of the <strong>{DATE} - {TIME}</strong>"
+        training_of_the_DATE_TIME_html: "Training of the <strong>{DATE} - {TIME}</strong>"
         you_can_validate_the_training_of_the_following_members: "Puede validar la formación de los siguientes miembros:"
         deleted_user: "Usario eliminado"
         no_reservation: "Sin reserva"
@@ -154,15 +149,13 @@ es:
         status_enabled: "Enabled"
         status_disabled: "Disabled"
         status_all: "All"
-
       trainings_new:
-        # create a new training
+        #create a new training
         add_a_new_training: "Add a new training"
         beware_when_creating_a_training_its_reservation_prices_are_initialized_to_zero: "Tenga cuidado, al crear una formación, sus precios de reserva se inicializan en cero."
         dont_forget_to_change_them_before_creating_slots_for_this_training: "No olvides cambiarlos antes de crear espacios para esta formación."
-
       events:
-        # events tracking and management
+        #events tracking and management
         events_monitoring: "Monitoreo de eventos"
         manage_filters: "Administrar filtros"
         fablab_events: "Eventos de Fablab"
@@ -174,8 +167,8 @@ es:
         on_DATE: "on {DATE}"
         from_DATE: "Desde {DATE}"
         from_TIME: "Desde {TIME}"
-        to_date: "to" # context: date. eg: 'from 01/01 to 01/05'
-        to_time: "to"  # context: time. eg. 'from 18:00 to 21:00'
+        to_date: '"to"'
+        to_time: '"to"'
         title: "Title"
         dates: "Dates"
         booking: "Booking"
@@ -215,22 +208,19 @@ es:
         do_you_really_want_to_delete_this_price_category: "¿Desea realmente eliminar esta categoría de precios?"
         price_category_successfully_deleted: "Categoría de precio eliminada correctamente."
         price_category_deletion_failed: "Error al eliminar la categoría de precio."
-
       events_new:
-        # add a new event
+        #add a new event
         add_an_event: "Add an event"
         none: "Nada"
         every_days: "Todos los dias"
         every_week: "Cada semana"
         every_month: "Cada mes"
         every_year: "Cada año"
-
       events_edit:
-        # edit an existing event
+        #edit an existing event
         edit_the_event: "Editar el evento"
-
       event_reservations:
-        # event reservations list
+        #event reservations list
         the_reservations: "Reservas :"
         user: "User"
         payment_date: "Fecha de pago"
@@ -240,9 +230,8 @@ es:
         no_reservations_for_now: "No hay reservas por ahora."
         back_to_monitoring: "Volver a monitorizar"
         canceled: "cancelada"
-
       pricing:
-        # subscriptions, prices, credits and coupons management
+        #subscriptions, prices, credits and coupons management
         pricing_management: "Gestión de precios"
         subscriptions: "Suscripciones"
         trainings: "Formaciones"
@@ -271,7 +260,7 @@ es:
         hours: "Slots of {DURATION} minutes"
         related_subscriptions: "Suscripciónes relacionada"
         please_specify_a_number: "Por favor, especifique un número."
-        none: "Nada"  # nota gramatical: concordancia con "formación".
+        none: '"Nada"'
         an_error_occurred_while_saving_the_number_of_credits: "Se ha producido un error al guardar el número de créditos."
         an_error_occurred_while_deleting_credit_with_the_TRAINING: "Se ha producido un error al eliminar el crédito con la {TRAINING}."
         an_error_occurred_unable_to_find_the_credit_to_revoke: "Se ha producido un error: no se puede encontrar el crédito a revocar."
@@ -321,26 +310,23 @@ es:
         status_enabled: "Enabled"
         status_disabled: "Disabled"
         status_all: "All"
-
       coupons_new:
-        # ajouter un code promotionnel
+        #ajouter un code promotionnel
         add_a_coupon: "Añadir un cupón"
         unable_to_create_the_coupon_check_code_already_used: "No se puede crear el cupón. Compruebe que el código no esté ya utilizado"
-
       coupons_edit:
-        # mettre à jour un code promotionnel
+        #mettre à jour un code promotionnel
         coupon: "Coupon:"
         unable_to_update_the_coupon_an_error_occurred: "No se puede actualizar el cupón: se ha producido un error."
-
       plans:
         new:
-          # add a subscription plan on the platform
+          #add a subscription plan on the platform
           add_a_subscription_plan: "Agregar un plan de suscripción"
           unable_to_create_the_subscription_please_try_again: "No se puede crear el plan de suscripción. Por favor, inténtelo de nuevo."
           successfully_created_subscriptions_dont_forget_to_redefine_prices: "Suscripción(es) creada correctamente. No olvide redefinir los precios."
           unable_to_save_this_user_check_that_there_isnt_an_already_a_user_with_the_same_name: "No se puede guardar este usuario. Compruebe que no hay un usuario ya definido con el mismo nombre."
         edit:
-          # edit a subscription plan / machine slot prices
+          #edit a subscription plan / machine slots prices
           subscription_plan: "Plan de suscripción:"
           prices: "Precios"
           copy_prices_from: "Copia los precios desde"
@@ -351,11 +337,10 @@ es:
           space: "Espacio"
           unable_to_save_subscription_changes_please_try_again: "No se pueden guardar los cambios de suscripción. Por favor, inténtelo de nuevo."
           subscription_successfully_changed: "Suscripción cambiada correctamente."
-
       invoices:
-        # list of all invoices & invoicing parameters
+        #list of all invoices & invoicing parameters
         invoices: "Facturas"
-        accounting_periods: "Accounting periods"       # missing translation
+        accounting_periods: "Accounting periods"
         invoices_list: "Lista de facturas"
         filter_invoices: "Filtrar facturas"
         invoice_num_: "Factura #:"
@@ -371,7 +356,7 @@ es:
         display_more_invoices: "Mostrar más facturas..."
         no_invoices_for_now: "Sin facturas por ahora."
         invoicing_settings: "Configuración de facturación"
-        warning_invoices_disabled: "Warning : invoices are not enabled. No invoices will be generated by Fab-manager. Nevertheless, you must correctly fill the information below, especially VAT."       # missing translation
+        warning_invoices_disabled: "Warning : invoices are not enabled. No invoices will be generated by Fab-manager. Nevertheless, you must correctly fill the information below, especially VAT."
         change_logo: "Cambio de logotipo"
         john_smith: "John Smith"
         john_smith_at_example_com: "jean.smith@example.com"
@@ -451,7 +436,7 @@ es:
         description: "Descripción"
         description_optional: "Descripción (opcional):"
         will_appear_on_the_refund_invoice: "Aparecerá en la factura de reembolso."
-        none: "Nada"  # grammar note: concordancia con "medio de pago""
+        none: "Nada\"  # grammar note: concordancia con \"medio de pago\""
         by_cash: "En efectivo"
         by_cheque: "Mediante cheque"
         by_transfer: "Por transferencia"
@@ -569,9 +554,8 @@ es:
           debit_euro: "Euro debit"
           credit_euro: "Euro credit"
           lettering: "Lettering"
-
       members:
-        # management of users, labels, groups, and so on
+        #management of users, labels, groups, and so on
         users_management: "Gestión de usuarios"
         members: "Miembros"
         subscriptions: "Subscriptions"
@@ -591,6 +575,7 @@ es:
         groups: "Grupos"
         tags: "Tags"
         authentication: "Autenticación"
+        confirmation_required: "Confirmation required"
         confirm_delete_member: "¿Desea realmente eliminar este usario? Esto no se puede deshacer."
         member_successfully_deleted: "Usario eliminado correctamente."
         unable_to_delete_the_member: "No se puede eliminar el usario."
@@ -645,14 +630,12 @@ es:
           status_enabled: "Enabled"
           status_disabled: "Disabled"
           status_all: "All"
-
       members_new:
-        # add a member
+        #add a member
         add_a_member: "Agregar un miembro"
         user_is_an_organization: "El usuario es una organización"
-
       members_import:
-        # members bulk import
+        #members bulk import
         import_members: "Import members"
         info: "You can upload a CSV file to create new members or update existing ones. Your file must user the identifiers below to specify the group, the trainings and the tags of the members."
         required_fields: "Your file must contain, at least, the following information for each user to create: email, name, first name and group. If the password is empty, it will be generated. On updates, the empty fields will be kept as is."
@@ -676,9 +659,8 @@ es:
         update_on_id: "ID"
         update_on_username: "Username"
         update_on_email: "Email address"
-
       members_import_result:
-        # import results
+        #import results
         import_results: "Import results"
         import_details: "Import #{ID}, of {DATE}, initiated by {USER}"
         results: "Results"
@@ -688,9 +670,8 @@ es:
         success: "Success"
         failed: "Failed"
         error_details: "Error's details:"
-
       members_edit:
-        # edit a member
+        #edit a member
         subscription: "Subscription"
         duration: "Duración:"
         expires_at: "Caduca en:"
@@ -732,9 +713,8 @@ es:
         a_problem_occurred_while_taking_the_subscription: "Se ha producido un problema al realizar la suscripción."
         wallet: "Wallet"
         to_credit: 'Credit'
-
       admins_new:
-        # add a new administrator to the platform
+        #add a new administrator to the platform
         add_an_administrator: "Agregar un administrador"
         administrator_successfully_created_he_will_receive_his_connection_directives_by_email: "administrador creado correctamente. {GENDER, select, female{She} other{He}} receive {GENDER, select, female{her} other{his}} directivas de conexión por e-mail."
         failed_to_create_admin: "No se puede crear el administrador :"
@@ -751,9 +731,8 @@ es:
         birth_date: "Date of birth"
         address: "Address"
         phone_number: "Phone number"
-
       authentication_new:
-        # add a new authentication provider (SSO)
+        #add a new authentication provider (SSO)
         local_database: "Base de datos local"
         o_auth2: "OAuth 2.0"
         add_a_new_authentication_provider: "Agregar un nuevo proveedor de autenticación"
@@ -766,21 +745,19 @@ es:
         do_you_really_want_to_continue: "¿De verdad quieres continuar?"
         unsecured_oauth2_provider_successfully_added: "Proveedor de OAuth 2.0 no seguro, se ha agregado correctamente."
         oauth2_provider_successfully_added: "OAuth 2.0 proveedor agregado correctamente."
-
       authentication_edit:
-        # edit an authentication provider (SSO)
+        #edit an authentication provider (SSO)
         provider: "Proveedor :"
         it_is_required_to_set_the_matching_between_User.uid_and_the_API_to_add_this_provider: "Es necesario establecer la coincidencia entre User.uid y la API para agregar este proveedor"
         provider_successfully_updated: "Proveedor actualizado correctamente"
         an_error_occurred_unable_to_update_the_provider: "Se ha producido un error: no se puede actualizar el proveedor."
-
       statistics:
-        # statistics tables
+        #statistics tables
         statistics: "Statistics"
         evolution: "Evolución"
         age_filter: "Filtro de edad"
-        from_age: "Desde"  # contexto: edad. por ejemplo: de 8 a 40 años
-        to_age: "a"  # contexto: edad. por ejemplo: de 8 a 40 años
+        from_age: "Desde" #context: age. eg: from 8 to 40 years old
+        to_age: "a" #context: age. eg: from 8 to 40 years old
         _years_old: "años"
         start: "Principio:"
         end: "Final:"
@@ -789,8 +766,8 @@ es:
         criterion: "Criterio:"
         value: "Valor:"
         exclude: "Excluir"
-        from_date: "From" # context: date. eg: 'from 01/01 to 01/05'
-        to_date: "to" # context: date. eg: 'from 01/01 to 01/05'
+        from_date: '"From"'
+        to_date: '"to"'
         entries: "Entradas:"
         revenue_: "Ingresos:"
         average_age: "Edad media:"
@@ -815,15 +792,14 @@ es:
         man: "Man"
         woman: "Woman"
         export_is_running_you_ll_be_notified_when_its_ready: "Export is running. You'll be notified when it's ready."
-
       stats_graphs:
-        # statistics graphs
+        #statistics graphs
         statistics: "Statistics"
         data: "Datos"
         day: "Dia"
         week: "Semana"
-        from_date: "From" # context: date. eg: 'from 01/01 to 01/05'
-        to_date: "to" # context: date. eg: 'from 01/01 to 01/05'
+        from_date: '"From"'
+        to_date: '"to"'
         month: "Month"
         start: "Inicio:"
         end: "Final:"
@@ -835,9 +811,8 @@ es:
         week_of_START_to_END: "Semana del {START} a {END}"
         no_data_for_this_period: "No hay datos para este periodo"
         date: "Date"
-
       settings:
-        # global application parameters and customization
+        #global application parameters and customization
         title: "Título"
         customize_the_application: "Personalizar la aplicación"
         general: "General"
@@ -960,7 +935,6 @@ es:
           publish_will_notify: "Publish a new version will send a notification to every users."
           publish: "Publish"
           users_notified: "Platform users will be notified of the update."
-
       open_api_clients:
         add_new_client: "Crear un nuevo cliente de API"
         api_documentation: "Documentation API"
@@ -978,21 +952,18 @@ es:
         client_successfully_updated: "Cliente actualizado correctamente."
         client_successfully_deleted: "Cliente borrado correctamente."
         access_successfully_revoked: "Acceso revocado correctamente."
-
       space_new:
-        # create a new space
+        #create a new space
         add_a_new_space: "Añadir un espacio nuevo"
         watch_out_when_creating_a_new_space_its_prices_are_initialized_at_0_for_all_subscriptions: "¡Cuidado! Al crear un nuevo espacio, sus precios se inicializan en 0 para todas las suscripciones."
         consider_changing_its_prices_before_creating_any_reservation_slot: "Considere cambiar sus precios antes de crear cualquier espacio de reserva."
         add_this_space: "Añadir este espacio"
-
       space_edit:
-        # modify an exiting space
+        #modify an exiting space
         edit_the_space_NAME: "Edit the space: {NAME}"
         validate_the_changes: "Validar los cambios"
-
       manage_abuses:
-        # process and delete abuses reports
+        #process and delete abuses reports
         abuses_list: "Lista de informes"
         no_reports: "No informes por ahora"
         published_by: "published by"